Instance CompSpecs : compspecs.

Lemma Znth_map2:
forall A B C (a: Inhabitant A) (b: Inhabitant B) (c: Inhabitant C) (f: A -> B -> C) (al: list A) (bl: list B) i,
Zlength al = Zlength bl ->
0 <= i < Zlength al ->
Znth i (map2 f al bl) = f (Znth i al) (Znth i bl).