simp_all

gistfile1.txt

[Elab.command] [4.214561s] set_option trace.Meta.Tactic.simp true in
    example (c k : ℕ) (hk : ∀ (b : ℕ), k * b = k * c → b = c) (b : ℕ) (h : S k * b = S k * c) : b = c :=
      by
      simp_all (config := { zeta := false, beta := false, eta := false, iota := false, proj := false, decide := false })
      sorry
  [Elab.command] [4.214447s] example (c k : ℕ) (hk : ∀ (b : ℕ), k * b = k * c → b = c) (b : ℕ) (h : S k * b = S k * c) :
          b = c :=
        by
        simp_all (config :=
          { zeta := false, beta := false, eta := false, iota := false, proj := false, decide := false })
        sorry
    [Elab.step] [0.001958s] expected type: Sort ?u.10050, term
        ∀ (b : ℕ), k * b = k * c → b = c
      [Elab.step] [0.001861s] expected type: Sort ?u.10053, term
          k * b = k * c → b = c
        [Elab.step] [0.001736s] expected type: Sort ?u.10054, term
            k * b = k * c
          [Elab.step] [0.001721s] expected type: Sort ?u.10054, term
              binrel% Eq✝ (k * b) (k * c)
    [Elab.step] [0.001301s] expected type: Sort ?u.10127, term
        S k * b = S k * c
      [Elab.step] [0.001291s] expected type: Sort ?u.10127, term
          binrel% Eq✝ (S k * b) (S k * c)
    [Elab.step] [4.204734s] 
          simp_all (config :=
            { zeta := false, beta := false, eta := false, iota := false, proj := false, decide := false })
          sorry
      [Elab.step] [4.204701s] 
            simp_all (config :=
              { zeta := false, beta := false, eta := false, iota := false, proj := false, decide := false })
            sorry
        [Elab.step] [4.203344s] simp_all (config :=
              { zeta := false, beta := false, eta := false, iota := false, proj := false, decide := false })
          [Compiler] [0.001734s] compiling new: [[email protected]._hyg.968]
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, k * c ==> c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.002208s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.002149s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.002018s] ❌ instHMul =?= instHMul
                [Meta.isDefEq.delta] [0.001111s] ❌ instHMul =?= instHMul
                  [Meta.isDefEq] [0.001073s] ❌ MulOneClass.toMul =?= MyNat.MyNat.instMulMyNat
                    [Meta.isDefEq] [0.001030s] ❌ MulOneClass.toMul =?= { mul := MyNat.MyNat.mul }
                      [Meta.isDefEq] [0.001006s] ❌ Monoid.toMulOneClass.2 =?= { mul := MyNat.MyNat.mul }
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001842s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001781s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001640s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001837s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001776s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001631s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001426s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001365s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001227s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001434s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001374s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001163s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001307s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001248s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001120s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001233s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001433s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001373s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001436s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001373s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                b = c
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @forall_exists_index:1000, failed to unify
                ∀ (h : ∃ x, ?p x), ?q h
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq:1000, failed to unify
                ∀ (a : ?α), a = ?a' → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq':1000, failed to unify
                ∀ (a : ?α), ?a' = a → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_or_imp:1000, failed to unify
                ∀ (a : ?α), a = ?a' ∨ ?q a → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?f a = b → ?p b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_apply_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), b = ?f a → ?p b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff₂:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?p a → ?f a = b → ?q b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Sum.forall:1000, failed to unify
                ∀ (x : ?α ⊕ ?β), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_left:1000, failed to unify
                ∀ {a : ?α}, a = ?b ↔ a = ?c
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_right:1000, failed to unify
                ∀ {c : ?α}, ?a = c ↔ ?b = c
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] forall_true_left:1000, failed to unify
                ∀ (x : True), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Nonempty.forall:1000, failed to unify
                ∀ (h : Nonempty ?α), ?p h
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @IsEmpty.forall_iff, failed to synthesize instance
                IsEmpty (k * b = c * k)
          [Meta.Tactic.simp.unify] @Prod.forall:1000, failed to unify
                ∀ (x : ?α × ?β), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Subtype.forall:1000, failed to unify
                ∀ (x : { a // ?p a }), ?q x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @OrderDual.forall:1000, failed to unify
                ∀ (a : ?αᵒᵈ), ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @imp_self:1000, failed to unify
                ?a → ?a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @forall_const, failed to synthesize instance
                Nonempty (k * b = c * k)
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001368s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001310s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001362s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001296s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001518s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001445s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001286s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                b = c
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @forall_exists_index:1000, failed to unify
                ∀ (h : ∃ x, ?p x), ?q h
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq:1000, failed to unify
                ∀ (a : ?α), a = ?a' → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq':1000, failed to unify
                ∀ (a : ?α), ?a' = a → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_or_imp:1000, failed to unify
                ∀ (a : ?α), a = ?a' ∨ ?q a → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?f a = b → ?p b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_apply_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), b = ?f a → ?p b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff₂:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?p a → ?f a = b → ?q b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Sum.forall:1000, failed to unify
                ∀ (x : ?α ⊕ ?β), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_left:1000, failed to unify
                ∀ {a : ?α}, a = ?b ↔ a = ?c
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_right:1000, failed to unify
                ∀ {c : ?α}, ?a = c ↔ ?b = c
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] forall_true_left:1000, failed to unify
                ∀ (x : True), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Nonempty.forall:1000, failed to unify
                ∀ (h : Nonempty ?α), ?p h
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @IsEmpty.forall_iff, failed to synthesize instance
                IsEmpty (k * b = c * k)
          [Meta.Tactic.simp.unify] @Prod.forall:1000, failed to unify
                ∀ (x : ?α × ?β), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Subtype.forall:1000, failed to unify
                ∀ (x : { a // ?p a }), ?q x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @OrderDual.forall:1000, failed to unify
                ∀ (a : ?αᵒᵈ), ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @imp_self:1000, failed to unify
                ?a → ?a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @forall_const, failed to synthesize instance
                Nonempty (k * b = c * k)
          [Meta.Tactic.simp.unify] @forall_exists_index:1000, failed to unify
                ∀ (h : ∃ x, ?p x), ?q h
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq:1000, failed to unify
                ∀ (a : ?α), a = ?a' → ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq':1000, failed to unify
                ∀ (a : ?α), ?a' = a → ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_or_imp:1000, failed to unify
                ∀ (a : ?α), a = ?a' ∨ ?q a → ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?f a = b → ?p b
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_apply_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), b = ?f a → ?p b
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff₂:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?p a → ?f a = b → ?q b
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Sum.forall:1000, failed to unify
                ∀ (x : ?α ⊕ ?β), ?p x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_left:1000, failed to unify
                ∀ {a : ?α}, a = ?b ↔ a = ?c
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_right:1000, failed to unify
                ∀ {c : ?α}, ?a = c ↔ ?b = c
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] forall_true_left:1000, failed to unify
                ∀ (x : True), ?p x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Nonempty.forall:1000, failed to unify
                ∀ (h : Nonempty ?α), ?p h
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @IsEmpty.forall_iff, failed to synthesize instance
                IsEmpty ℕ
          [Meta.Tactic.simp.unify] @Prod.forall:1000, failed to unify
                ∀ (x : ?α × ?β), ?p x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Subtype.forall:1000, failed to unify
                ∀ (x : { a // ?p a }), ?q x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @OrderDual.forall:1000, failed to unify
                ∀ (a : ?αᵒᵈ), ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001339s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001150s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001437s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                b = c
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @forall_exists_index:1000, failed to unify
                ∀ (h : ∃ x, ?p x), ?q h
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq:1000, failed to unify
                ∀ (a : ?α), a = ?a' → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq':1000, failed to unify
                ∀ (a : ?α), ?a' = a → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_or_imp:1000, failed to unify
                ∀ (a : ?α), a = ?a' ∨ ?q a → ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?f a = b → ?p b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_apply_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), b = ?f a → ?p b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff₂:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?p a → ?f a = b → ?q b
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Sum.forall:1000, failed to unify
                ∀ (x : ?α ⊕ ?β), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_left:1000, failed to unify
                ∀ {a : ?α}, a = ?b ↔ a = ?c
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_right:1000, failed to unify
                ∀ {c : ?α}, ?a = c ↔ ?b = c
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] forall_true_left:1000, failed to unify
                ∀ (x : True), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Nonempty.forall:1000, failed to unify
                ∀ (h : Nonempty ?α), ?p h
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @IsEmpty.forall_iff, failed to synthesize instance
                IsEmpty (k * b = c * k)
          [Meta.Tactic.simp.unify] @Prod.forall:1000, failed to unify
                ∀ (x : ?α × ?β), ?p x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Subtype.forall:1000, failed to unify
                ∀ (x : { a // ?p a }), ?q x
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @OrderDual.forall:1000, failed to unify
                ∀ (a : ?αᵒᵈ), ?p a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @imp_self:1000, failed to unify
                ?a → ?a
              with
                k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @forall_const, failed to synthesize instance
                Nonempty (k * b = c * k)
          [Meta.Tactic.simp.unify] @forall_exists_index:1000, failed to unify
                ∀ (h : ∃ x, ?p x), ?q h
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq:1000, failed to unify
                ∀ (a : ?α), a = ?a' → ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq':1000, failed to unify
                ∀ (a : ?α), ?a' = a → ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_or_imp:1000, failed to unify
                ∀ (a : ?α), a = ?a' ∨ ?q a → ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?f a = b → ?p b
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_eq_apply_imp_iff:1000, failed to unify
                ∀ (b : ?β) (a : ?α), b = ?f a → ?p b
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @forall_apply_eq_imp_iff₂:1000, failed to unify
                ∀ (b : ?β) (a : ?α), ?p a → ?f a = b → ?q b
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Sum.forall:1000, failed to unify
                ∀ (x : ?α ⊕ ?β), ?p x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_left:1000, failed to unify
                ∀ {a : ?α}, a = ?b ↔ a = ?c
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @eq_iff_eq_cancel_right:1000, failed to unify
                ∀ {c : ?α}, ?a = c ↔ ?b = c
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] forall_true_left:1000, failed to unify
                ∀ (x : True), ?p x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Nonempty.forall:1000, failed to unify
                ∀ (h : Nonempty ?α), ?p h
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] @IsEmpty.forall_iff, failed to synthesize instance
                IsEmpty ℕ
          [Meta.Tactic.simp.unify] @Prod.forall:1000, failed to unify
                ∀ (x : ?α × ?β), ?p x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @Subtype.forall:1000, failed to unify
                ∀ (x : { a // ?p a }), ?q x
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.unify] @OrderDual.forall:1000, failed to unify
                ∀ (a : ?αᵒᵈ), ?p a
              with
                ∀ (b : ℕ), k * b = c * k → b = c
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001373s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001309s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001173s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.synthInstance] [0.002034s] ❌ IsRightCancelMul ℕ
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001479s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001416s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001231s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001302s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001159s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001312s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001252s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001122s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001435s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001367s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001229s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001337s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001276s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001131s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001295s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001323s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001262s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001130s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001371s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001225s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001160s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001354s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001296s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001318s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001258s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001121s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001128s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?c = ?b * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?c =?= k * (k * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001271s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001437s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?c = ?b * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?c =?= k * (k * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001265s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001127s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?c = ?b * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?c =?= k * (k * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001432s] ❌ ?a * ?b = ?a * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001368s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001228s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001143s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001318s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001258s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001127s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * (k * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?a * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, k * c ==> c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.rewrite] @eq_self:1000, c * k = c * k ==> True
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001155s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001326s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001266s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001131s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001319s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001260s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001127s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001230s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001323s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001262s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001132s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * k) ==> k * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001317s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001258s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001122s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001435s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001373s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001228s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?c = ?b * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?c =?= k * (k * k)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?a * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001232s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001333s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?b =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?c = ?b * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?c =?= k * (k * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * k) = c * k
          [Meta.isDefEq] [0.001430s] ❌ ?a * ?b = ?a * ?c =?= k * (k * k) = c * k
            [Meta.isDefEq] [0.001366s] ❌ ?a * ?b =?= k * (k * k)
              [Meta.isDefEq] [0.001226s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001345s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001158s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001340s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001135s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * k = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * k = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?b =?= k * k = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * k = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] @mul_left_inj, failed to synthesize instance
                IsRightCancelMul ℕ
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?c = ?b * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?c =?= k * k
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * k = c * k
          [Meta.isDefEq] [0.001432s] ❌ ?a * ?b = ?a * ?c =?= k * k = c * k
            [Meta.isDefEq] [0.001368s] ❌ ?a * ?b =?= k * k
              [Meta.isDefEq] [0.001230s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * MyNat.S k ==> MyNat.S k * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, k * MyNat.S k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k + k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k + k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * k + k ==> k + k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.002335s] ❌ ?a + ?b = ?a =?= k + k * k = c * k
            [Meta.isDefEq] [0.002278s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.002061s] ❌ instHAdd =?= instHAdd
                [Meta.isDefEq.delta] [0.001169s] ❌ instHAdd =?= instHAdd
                  [Meta.isDefEq] [0.001124s] ❌ AddZeroClass.toAdd =?= MyNat.instAdd
                    [Meta.isDefEq] [0.001081s] ❌ AddZeroClass.toAdd =?= { add := MyNat.add }
                      [Meta.isDefEq] [0.001063s] ❌ AddMonoid.toAddZeroClass.2 =?= { add := MyNat.add }
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001943s] ❌ ?a + ?b = ?b =?= k + k * k = c * k
            [Meta.isDefEq] [0.001882s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001688s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001426s] ❌ ?a + ?b = ?a =?= k + k * k = c * k
            [Meta.isDefEq] [0.001369s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001191s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001402s] ❌ ?a + ?b = ?b =?= k + k * k = c * k
            [Meta.isDefEq] [0.001338s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001160s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * MyNat.S k ==> MyNat.S k * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, k * MyNat.S k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k + k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k + k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * k + k ==> k + k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001427s] ❌ ?a + ?b = ?a =?= k + k * k = c * k
            [Meta.isDefEq] [0.001350s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001169s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001408s] ❌ ?a + ?b = ?b =?= k + k * k = c * k
            [Meta.isDefEq] [0.001346s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001168s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001417s] ❌ ?a + ?b = ?a =?= k + k * k = c * k
            [Meta.isDefEq] [0.001356s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001166s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001584s] ❌ ?a + ?b = ?b =?= k + k * k = c * k
            [Meta.isDefEq] [0.001501s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001272s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * MyNat.S k ==> MyNat.S k * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, k * MyNat.S k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k + k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k + k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * k + k ==> k + k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001894s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001794s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001550s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.002000s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001854s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001586s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001000s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.002095s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001932s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001625s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001031s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.002398s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.002229s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001903s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001207s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
                  [Meta.isDefEq] [0.001142s] ❌ fun a b ↦ Mul.mul a b =?= fun a b ↦ Mul.mul a b
                    [Meta.isDefEq] [0.001102s] ❌ Mul.mul a b =?= Mul.mul a b
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001608s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001543s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001379s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001497s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001424s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001364s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001163s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001314s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001255s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001124s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001437s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001556s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001490s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001334s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001617s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001519s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001328s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * MyNat.S k ==> MyNat.S k * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, k * MyNat.S k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k + k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * k + k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k + k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * k + k ==> k + k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001392s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001333s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001187s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001131s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001331s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001276s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001144s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001426s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001365s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001227s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * k + k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * k + k ==> k + k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001148s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001139s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001325s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001266s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001423s] ❌ ?a + ?b = ?a =?= k + k * k = c * k
            [Meta.isDefEq] [0.001356s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001168s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001420s] ❌ ?a + ?b = ?b =?= k + k * k = c * k
            [Meta.isDefEq] [0.001355s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001173s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k + k * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k + k * k) ==> (k + k * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001358s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001167s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001282s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001148s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001419s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001358s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001221s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001328s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001135s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001275s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?b =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?c = ?b * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?c =?= k * (k + k * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k + k * k) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * (k + k * k) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (k + k * k)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k + k * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected k + k * k ==> k * k + k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001413s] ❌ ?a + ?b = ?a =?= k + k * k = c * k
            [Meta.isDefEq] [0.001356s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001171s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                k + k * k = c * k
          [Meta.isDefEq] [0.001414s] ❌ ?a + ?b = ?b =?= k + k * k = c * k
            [Meta.isDefEq] [0.001355s] ❌ ?a + ?b =?= k + k * k
              [Meta.isDefEq] [0.001165s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                k + k * k = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * MyNat.S k = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001364s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001306s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001374s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001233s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001367s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001310s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001181s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001267s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001131s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001268s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001436s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001372s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001340s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001429s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001367s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001229s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001141s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001310s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001250s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001106s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * b = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001360s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001302s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001172s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001282s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001374s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001130s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001486s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001341s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001275s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001159s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001315s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001255s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001123s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001328s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001321s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001262s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001132s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001436s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001373s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001437s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001373s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001337s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001342s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001428s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001367s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001229s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001337s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001151s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001144s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001511s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001447s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001301s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001506s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001428s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001279s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001405s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001344s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001189s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001385s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001313s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001165s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.isDefEq] [0.001493s] ❌ ?a * ?b = ?a =?= k * b = c * k
            [Meta.isDefEq] [0.001428s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?b =?= k * b = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * b = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?c = ?b * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?c =?= k * b
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * b = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?a * ?c =?= k * b = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * b
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * b = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * b = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (MyNat.S k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (MyNat.S k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (MyNat.S k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (MyNat.S k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, MyNat.S k * b ==> b * MyNat.S k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected b * MyNat.S k ==> MyNat.S k * b
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, b * MyNat.S k ==> b * k + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, b * k ==> k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001365s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001303s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001328s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001434s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001372s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001354s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001155s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001507s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001436s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (MyNat.S k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, MyNat.S k * b ==> b * MyNat.S k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected b * MyNat.S k ==> MyNat.S k * b
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, b * MyNat.S k ==> b * k + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001314s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001253s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001115s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001428s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001366s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001229s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001158s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001503s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001276s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected b * MyNat.S k ==> MyNat.S k * b
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, b * MyNat.S k ==> b * k + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, b * k ==> k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001376s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001317s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001181s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001270s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001356s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001267s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001125s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, b * k ==> k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001293s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001354s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001435s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001371s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001233s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001232s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001352s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001293s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001155s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001266s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001127s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001286s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001151s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001331s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001271s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001123s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001233s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001286s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001318s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001259s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001125s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001372s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001230s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001479s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001418s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001325s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001261s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001121s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001479s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001322s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001331s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001271s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001482s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001416s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001296s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001339s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001279s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001435s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001373s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001493s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001431s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001288s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001324s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001267s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001137s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001364s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001307s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001171s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001326s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001257s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001124s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001370s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001232s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001362s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001304s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001168s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001328s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001267s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001124s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001122s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001508s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001434s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001339s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001371s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001228s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001356s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001298s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001166s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001341s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001276s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001374s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001326s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001132s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001271s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (MyNat.S k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, MyNat.S k * b ==> b * MyNat.S k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected b * MyNat.S k ==> MyNat.S k * b
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, b * MyNat.S k ==> b * k + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001382s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001321s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001188s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001340s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001276s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected b * MyNat.S k ==> MyNat.S k * b
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, b * MyNat.S k ==> b * k + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001155s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001360s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001296s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001339s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001141s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001331s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001143s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001402s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001331s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001173s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.002291s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.002145s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001810s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001172s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
                  [Meta.isDefEq] [0.001097s] ❌ fun a b ↦ Mul.mul a b =?= fun a b ↦ Mul.mul a b
                    [Meta.isDefEq] [0.001058s] ❌ Mul.mul a b =?= Mul.mul a b
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.002207s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.002020s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001758s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001035s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.002196s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.002080s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001798s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001142s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
                  [Meta.isDefEq] [0.001066s] ❌ fun a b ↦ Mul.mul a b =?= fun a b ↦ Mul.mul a b
                    [Meta.isDefEq] [0.001025s] ❌ Mul.mul a b =?= Mul.mul a b
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.002287s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.002136s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001860s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001195s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
                  [Meta.isDefEq] [0.001131s] ❌ fun a b ↦ Mul.mul a b =?= fun a b ↦ Mul.mul a b
                    [Meta.isDefEq] [0.001100s] ❌ Mul.mul a b =?= Mul.mul a b
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001551s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001484s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001332s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001266s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001126s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001372s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001313s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001176s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001148s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001159s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001322s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001260s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001125s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001345s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001286s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001340s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001367s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001308s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001178s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001321s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001261s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001123s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001345s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001339s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001279s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001377s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001233s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected b * MyNat.S k ==> MyNat.S k * b
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, b * MyNat.S k ==> b * k + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, b * k ==> k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001384s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001318s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001184s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001305s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001176s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001337s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, b * k ==> k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001148s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001279s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001150s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001137s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001282s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001232s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001293s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001352s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001151s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001139s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001422s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001151s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001168s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001322s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001260s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001128s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001130s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001163s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001322s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001262s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001268s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001383s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001232s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, b * k ==> k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001377s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001316s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001177s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001379s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001314s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001168s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001497s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001426s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001431s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001366s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001228s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001358s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001282s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001497s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001434s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001283s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001345s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001148s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001435s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001368s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001228s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001409s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001350s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001219s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001122s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001275s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001143s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001510s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001447s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001302s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001479s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001270s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001336s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001491s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001425s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001284s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001356s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001160s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001339s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001279s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001342s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001385s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001322s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001183s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001504s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001433s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001274s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001276s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001323s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001127s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001520s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001458s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001295s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001298s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001342s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001279s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b + b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001380s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001320s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001186s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001366s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001303s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001352s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001295s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001487s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001424s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001498s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001437s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001292s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001150s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001341s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001274s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001374s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001315s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001183s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001332s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001422s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001277s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001437s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001368s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001223s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001402s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001338s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001195s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001239s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001342s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001333s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001266s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001132s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001491s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001428s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001287s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001491s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001426s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001286s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001324s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001263s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001123s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001422s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001364s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001201s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001442s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001305s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001143s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001494s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001431s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001286s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001150s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001488s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001426s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001282s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b + b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, k * b + b ==> b + k * b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001401s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001340s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001191s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001265s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001333s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001271s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001498s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001270s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001489s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001426s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001279s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001376s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001314s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001179s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001326s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001130s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001509s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001443s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001300s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001373s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001306s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001160s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001325s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001258s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001125s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001233s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001362s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001303s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001407s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001346s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001176s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001499s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001438s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001366s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001306s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001143s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001322s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001256s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001121s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001518s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001455s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001311s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (k * b)) ==> k * (k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001371s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001313s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001179s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001327s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001418s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001385s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001321s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001187s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001354s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001479s] ❌ ?a * ?b = ?a =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?b =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?c =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (k * b)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (k * b))
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * b) ==> k * b * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001382s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001320s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001183s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001340s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001479s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001416s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001500s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001436s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001296s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001144s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?b =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?c =?= k * (k * b)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * b) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?a * ?c =?= k * (k * b) = c * k
            [Meta.isDefEq] [0.001374s] ❌ ?a * ?b =?= k * (k * b)
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * b ==> b * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001418s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001354s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001208s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001364s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001192s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001530s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001450s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001280s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001431s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001370s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001224s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001375s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001216s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001632s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001535s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001333s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001501s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001438s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001280s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001275s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001485s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001423s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001271s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001368s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001301s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001166s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001370s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001444s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001373s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001315s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001183s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001318s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001257s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001121s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001500s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001439s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001294s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001375s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001318s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001187s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001329s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001266s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001499s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001438s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001291s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001168s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001323s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001262s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001235s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001420s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001496s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001430s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001290s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001371s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001311s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001167s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001329s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001260s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001125s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?b =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?c =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (b + k * b)) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * (k * (b + k * b))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001148s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001384s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001323s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001174s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001517s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001450s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001301s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001360s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001167s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001322s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001261s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001129s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001545s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001483s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001320s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001497s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, k * c ==> c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.rewrite] @eq_self:1000, c * k = c * k ==> True
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * c = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * c = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, k * c ==> c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.rewrite] @eq_self:1000, c * k = c * k ==> True
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, k * c ==> c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001383s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001320s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001185s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001520s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001454s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001305s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001173s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001487s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001502s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001436s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001276s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, k * c ==> c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001360s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001298s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001419s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001350s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001210s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001485s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001418s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001298s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001354s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001498s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001433s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001594s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001520s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001351s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001510s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001445s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001295s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.rewrite] @eq_self:1000, c * k = c * k ==> True
          [Meta.Tactic.simp.discharge] >> discharge?: k * (MyNat.S k * c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (MyNat.S k * c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (MyNat.S k * c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (MyNat.S k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, MyNat.S k * c ==> c * MyNat.S k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * MyNat.S k ==> MyNat.S k * c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, c * MyNat.S k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001385s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001321s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001186s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001492s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001427s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001283s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001385s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001319s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001181s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001132s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (MyNat.S k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, MyNat.S k * c ==> c * MyNat.S k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * MyNat.S k ==> MyNat.S k * c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, c * MyNat.S k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001377s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001320s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001182s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001415s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001352s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001209s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001293s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001314s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001252s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001119s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001486s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001419s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001527s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001465s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001315s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001489s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001419s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * MyNat.S k ==> MyNat.S k * c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, c * MyNat.S k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001378s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001320s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001178s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001390s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001326s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001192s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001366s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001372s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001313s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001172s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001356s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001158s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001526s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001460s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001311s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001491s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001487s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001420s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001277s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001349s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001290s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001496s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001430s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001285s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001521s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001457s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001307s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001511s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001441s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001289s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001372s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001306s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001172s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001374s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001306s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001229s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001518s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001445s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001283s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001497s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001434s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001279s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001366s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001332s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001128s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001665s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001593s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001421s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001531s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001468s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001306s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001367s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001307s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001377s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001312s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001176s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001369s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001310s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001175s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001380s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001317s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001178s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001416s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001268s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001352s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001664s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001573s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001377s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001498s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001425s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001270s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001504s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001436s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001280s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001305s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001703s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001632s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001440s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001556s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001453s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001289s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001376s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001318s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001183s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001342s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001139s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001501s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001438s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001282s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001375s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001301s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001493s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001425s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001499s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001423s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001272s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001374s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001229s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001489s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001422s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001268s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001687s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001604s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001412s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001488s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001425s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001277s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001497s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001425s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001281s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (MyNat.S k * c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, MyNat.S k * c ==> c * MyNat.S k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * MyNat.S k ==> MyNat.S k * c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, c * MyNat.S k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001379s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001319s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001185s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001337s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001625s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001560s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001399s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001510s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001426s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001274s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001374s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001313s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001177s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001147s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001485s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001434s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001371s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001230s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001482s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001419s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * MyNat.S k ==> MyNat.S k * c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, c * MyNat.S k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001428s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001365s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001217s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001440s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001361s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001188s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001490s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001419s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001361s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001341s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001141s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001534s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001464s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001298s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001621s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001511s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001346s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001512s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001449s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001301s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001151s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001319s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001257s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001127s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001486s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001375s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001315s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001174s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001295s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001489s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001363s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001185s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001448s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001370s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001212s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001511s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001439s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001278s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001520s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001456s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001304s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001302s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001135s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001391s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001447s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001413s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001270s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001354s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001150s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001441s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001378s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001482s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001241s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001375s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001297s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001494s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001429s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001274s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001237s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001162s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001345s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001131s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001517s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001450s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001277s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001605s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001523s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001362s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001506s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001440s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001289s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001360s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001301s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001168s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001281s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001238s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001522s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001454s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001304s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * MyNat.S k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * MyNat.S k ==> MyNat.S k * c
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_S:1000, c * MyNat.S k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001393s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001333s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001196s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001278s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001142s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001502s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001432s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001277s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001446s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001382s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001504s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001440s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001296s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001365s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001365s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001306s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001174s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001286s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001135s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001488s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001422s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001370s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001309s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001173s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001332s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001423s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001363s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001224s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001386s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001319s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001176s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001531s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001455s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001283s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001524s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001450s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001482s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?c =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001476s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001407s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001286s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001151s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001330s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?c =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001380s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001321s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001186s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001149s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001459s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?c =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001383s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001316s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001343s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001137s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001422s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001270s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?c =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001341s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001277s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001144s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001286s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001137s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001589s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001510s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001322s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.002399s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.002215s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001911s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001220s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
                  [Meta.isDefEq] [0.001144s] ❌ fun a b ↦ Mul.mul a b =?= fun a b ↦ Mul.mul a b
                    [Meta.isDefEq] [0.001100s] ❌ Mul.mul a b =?= Mul.mul a b
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001849s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001762s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001504s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001003s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.002327s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.002140s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001864s] ❌ instHMul =?= instHMul
                [Meta.isDefEq] [0.001166s] ❌ { hMul := fun a b ↦ Mul.mul a b } =?= { hMul := fun a b ↦ Mul.mul a b }
                  [Meta.isDefEq] [0.001088s] ❌ fun a b ↦ Mul.mul a b =?= fun a b ↦ Mul.mul a b
                    [Meta.isDefEq] [0.001046s] ❌ Mul.mul a b =?= Mul.mul a b
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (k * (c * k)) ==> k * (c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.002016s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001893s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001589s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001633s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001496s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001288s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001570s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001494s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001300s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001390s] ❌ ?a * ?c =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001234s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001369s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001309s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001173s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001324s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001261s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001126s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001618s] ❌ ?a * ?b = ?a =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001541s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001374s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001565s] ❌ ?a * ?b = ?b =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001475s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001317s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?c =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.isDefEq] [0.001512s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c * k)) = c * k
            [Meta.isDefEq] [0.001439s] ❌ ?a * ?b =?= k * (k * (c * k))
              [Meta.isDefEq] [0.001294s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c * k) ==> c * k * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001360s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001294s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001144s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001344s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?b = ?a =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001455s] ❌ ?a * ?b = ?b =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?c = ?b * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?c =?= k * (c * k)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c * k) = c * k
          [Meta.isDefEq] [0.001463s] ❌ ?a * ?b = ?a * ?c =?= k * (c * k) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected c * k ==> k * c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c * k + c) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001366s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001308s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001175s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001284s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001150s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001265s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001358s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001240s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001158s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001335s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001135s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001470s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001293s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001161s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001332s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001272s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001140s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001258s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001416s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001276s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001379s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001320s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001187s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001155s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001483s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001419s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001268s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001419s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001263s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001166s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001282s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001268s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001361s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001303s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001164s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001337s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001478s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001415s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001275s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001246s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001352s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001293s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001153s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001364s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001307s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001160s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001331s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001269s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001488s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001422s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001414s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001266s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001361s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001301s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001159s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001371s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001300s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001160s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001380s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001388s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c * k + c) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, c * k + c ==> c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001380s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001319s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001160s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001288s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001141s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001402s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001409s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001269s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001351s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001285s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001152s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001346s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001283s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001397s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001480s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001417s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001276s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001380s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001321s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001183s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001273s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001138s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001467s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001259s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001255s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001334s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001137s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001297s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001163s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001462s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001399s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001456s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001412s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001272s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001445s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001370s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001230s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001362s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001302s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001169s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001347s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001133s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001454s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001251s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001361s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001292s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001159s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001348s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001280s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001145s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001271s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001256s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001401s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001451s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001387s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (c + c * k))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (c + c * k)) ==> k * (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001368s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001307s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001174s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001287s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001146s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001395s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001248s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001466s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001404s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001473s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001411s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001453s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001385s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001379s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001317s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001180s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001338s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001275s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001139s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001396s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?b =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001250s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001484s] ❌ ?a * ?c = ?b * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001421s] ❌ ?a * ?c =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.isDefEq] [0.001457s] ❌ ?a * ?b = ?a * ?c =?= k * (k * (c + c * k)) = c * k
            [Meta.isDefEq] [0.001392s] ❌ ?a * ?b =?= k * (k * (c + c * k))
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (c + c * k)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (c + c * k) ==> (c + c * k) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001298s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001166s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001326s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001264s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001131s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001481s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001420s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001389s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001243s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001477s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001416s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001273s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001471s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001403s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001355s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001158s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001331s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001270s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001135s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001464s] ❌ ?a * ?b = ?a =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001254s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001443s] ❌ ?a * ?b = ?b =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001381s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001242s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001499s] ❌ ?a * ?c = ?b * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001437s] ❌ ?a * ?c =?= k * (c + c * k)
              [Meta.isDefEq] [0.001274s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (c + c * k) = c * k
          [Meta.isDefEq] [0.001460s] ❌ ?a * ?b = ?a * ?c =?= k * (c + c * k) = c * k
            [Meta.isDefEq] [0.001394s] ❌ ?a * ?b =?= k * (c + c * k)
              [Meta.isDefEq] [0.001249s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (c + c * k) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected c + c * k ==> c * k + c
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                b + k * b = c + c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_add_right:1000, failed to unify
                ?a = ?a + ?b
              with
                b + k * b = c + c * k
          [Meta.Tactic.simp.unify] @self_eq_add_left:1000, failed to unify
                ?b = ?a + ?b
              with
                b + k * b = c + c * k
          [Meta.isDefEq] [0.001439s] ❌ ?a + ?b = ?a =?= b + k * b = c + c * k
            [Meta.isDefEq] [0.001379s] ❌ ?a + ?b =?= b + k * b
              [Meta.isDefEq] [0.001209s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_right_eq_self:1000, failed to unify
                ?a + ?b = ?a
              with
                b + k * b = c + c * k
          [Meta.isDefEq] [0.001417s] ❌ ?a + ?b = ?b =?= b + k * b = c + c * k
            [Meta.isDefEq] [0.001348s] ❌ ?a + ?b =?= b + k * b
              [Meta.isDefEq] [0.001175s] ❌ instHAdd =?= instHAdd
          [Meta.Tactic.simp.unify] @add_left_eq_self:1000, failed to unify
                ?a + ?b = ?b
              with
                b + k * b = c + c * k
          [Meta.Tactic.simp.unify] @add_right_inj:1000, failed to unify
                ?a + ?b = ?a + ?c
              with
                b + k * b = c + c * k
          [Meta.Tactic.simp.unify] @add_left_inj:1000, failed to unify
                ?b + ?a = ?c + ?a
              with
                b + k * b = c + c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001372s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001311s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001176s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001329s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001268s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001134s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001486s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001423s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001438s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001376s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001236s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001488s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001425s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001284s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001474s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001405s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001261s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001350s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001289s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001156s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001340s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001274s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001136s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001469s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001408s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001450s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001244s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001472s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001252s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001458s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001393s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001253s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001357s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001299s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001163s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001363s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001301s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001154s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001482s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001418s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001267s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001465s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001400s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001257s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001468s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001406s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001260s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001449s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001384s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @self_eq_mul_left:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @left_eq_mul₀:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @right_eq_mul₀:1000, failed to unify
                ?b = ?a * ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001359s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001301s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001170s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_right_eq_self:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001353s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001291s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001157s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_left_eq_self:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001461s] ❌ ?a * ?b = ?a =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001398s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001245s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_left₀:1000, failed to unify
                ?a * ?b = ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001475s] ❌ ?a * ?b = ?b =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001410s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001262s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_right₀:1000, failed to unify
                ?a * ?b = ?b
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_right_inj:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.unify] @mul_left_inj:1000, failed to unify
                ?b * ?a = ?c * ?a
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001486s] ❌ ?a * ?c = ?b * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001423s] ❌ ?a * ?c =?= k * (b + k * b)
              [Meta.isDefEq] [0.001264s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_right_iff:1000, failed to unify
                ?a * ?c = ?b * ?c
              with
                k * (b + k * b) = c * k
          [Meta.isDefEq] [0.001452s] ❌ ?a * ?b = ?a * ?c =?= k * (b + k * b) = c * k
            [Meta.isDefEq] [0.001386s] ❌ ?a * ?b =?= k * (b + k * b)
              [Meta.isDefEq] [0.001247s] ❌ instHMul =?= instHMul
          [Meta.Tactic.simp.unify] @mul_eq_mul_left_iff:1000, failed to unify
                ?a * ?b = ?a * ?c
              with
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (b + k * b) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.add_comm:1000:perm, perm rejected b + k * b ==> k * b + b
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k * (b + k * b) ==> (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.discharge] >> discharge?: k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.discharge] maximum discharge depth has been reached
          [Meta.Tactic.simp.discharge] _uniq.11668, failed to discharge hypotheses
                k * (k * (k * (b + k * b))) = c * k
          [Meta.Tactic.simp.rewrite] MyNat.MyNat.mul_comm:1000:perm, perm rejected k *
                (k * (b + k * b)) ==> k * (b + k * b) * k
          [Meta.Tactic.simp.unify] @eq_self:1000, failed to unify
                ?a = ?a
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp.discharge] @eq_iff_true_of_subsingleton, failed to synthesize instance
                Subsingleton ℕ
          [Meta.Tactic.simp.unify] @self_eq_mul_right:1000, failed to unify
                ?a = ?a * ?b
              with
                k * (k * (b + k * b)) = c * k
          [Meta.Tactic.simp