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@mstewartgallus
Last active July 26, 2026 23:33
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Draft of antisymmetric logic
Trying to figure out an odd kind of anti-symmetric calculus. Just very awkward to work with substructural logic.
The trouble is that a double category sort of thing where the source object is the composition of several spans is really awkward to work with. Anti-symmetry is an attempt to approach things from the opposite perspective of apartness instead of equivalence and groupoids.
t ::= 𝔻 | 1 | tβ‚€ ∧ t₁ | ⋆t
─── id
t ⊒ t
Ξ“, tβ‚€, Ξ”, t₁, Ξ£, tβ‚‚, Ξ  ⊒ t₃
───────────── 1/2-exchange
Ξ“, tβ‚‚, Ξ”, tβ‚€, Ξ£, t₁, Ξ  ⊒ t₃
─── 1-intro
⊒ 1
Ξ” ⊒ t
Ξ“ ⊒ 1
────── 1-elim
Ξ“, Ξ” ⊒ t
Ξ“, tβ‚€, Ξ”, t₁, Ξ£ ⊒ tβ‚‚
────────── ⋆-intro
Ξ“, t₁, Ξ”, tβ‚€, Ξ£ ⊒ ⋆tβ‚‚
Ξ“, tβ‚€, Ξ”, t₁, Ξ£ ⊒ *tβ‚‚
────────── ⋆-elim
Ξ“, t₁, Ξ”, tβ‚€, Ξ£ ⊒ tβ‚‚
Ξ“ ⊒ tβ‚€
Ξ” ⊒ t₁
──────── ∧-intro
Ξ“, Ξ” ⊒ tβ‚€ ∧ t₁
tβ‚€, t₁, Ξ” ⊒ tβ‚‚
Ξ“ ⊒ tβ‚€ ∧ t₁
──────── ∧-elim
Ξ“, Ξ” ⊒ tβ‚‚
Derived types and terms.
Define
Ο‰ ≑ ⋆1
tβ‚€ ∨ t₁ ≑ ⋆(⋆tβ‚€ ∧ ⋆t₁)
∎
Lemma
Ο€ odd
Ο€ β€’ Ξ“ ⊒ ⋆t
────── ⋆-Ο€-elim
Ξ“ ⊒ t
Proof
Group theory Β―\_(ツ)_/Β―
∎
Lemma
Ο€ odd
Ξ“ ⊒ ⋆t
────── ⋆-Ο€-inv-elim
Ο€ β€’ Ξ“ ⊒ t
Proof
Β―\_(ツ)_/Β―
∎
Lemma
Ξ” ⊒ Ο‰
Ξ“ ⊒ Ο‰
───── Ο‰-elim
Ξ”, Ξ“ ⊒ 1
Proof
──── H2
- Ξ“ ⊒ Ο‰
────── H1
Ξ” ⊒ Ο‰
───── ⋆-Ο€-inv-elim
- Ο€ β€’ Ξ” ⊒ 1
─────── 1-elim
Ο€ β€’ Ξ”, Ξ“ ⊒ Ο‰
───────── {equivalent for some Ο€'}
Ο€' β€’ (Ξ”, Ξ“) ⊒ Ο‰
─────── ⋆-Ο€-elim
Ξ”, Ξ“ ⊒ 1
∎
Theorem
Ξ“ ⊒ tβ‚€
Ξ”, tβ‚€, K ⊒ t₁
─────── cut
Ξ”, Ξ“, K ⊒ t₁
FIXME
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