F-bounded Polymorphism in Typed Clojure

fbound.clj

; y has upper bound x, z has upper bound (Seqable y)
typed.core=> (ann foo (All [x [y :< x] [z :< (Seqable y)]] 
                           [x y z -> Any]))
[typed.core/foo (All [x [y :< x] [z :< (clojure.lang.Seqable y)]] (Fn [x y z -> Any]))]
typed.core=> (declare foo)
#'typed.core/foo

;cf = check-form
typed.core=> (cf (foo 2 2 [2]))
Any
typed.core=> (cf (foo 2 2 [1]))
#<AssertionError java.lang.AssertionError: Assert failed: Inferred type (Vector* (Value 1)) is not between bounds Nothing and (clojure.lang.Seqable (Value 2))
(and (subtype? inferred upper-bound) (subtype? lower-bound inferred))>

typed.core=> (cf (foo 2 1 [2]))
#<AssertionError java.lang.AssertionError: Assert failed: Inferred type (Vector* (Value 2)) is not between bounds Nothing and (clojure.lang.Seqable (Value 1))
(and (subtype? inferred upper-bound) (subtype? lower-bound inferred))>