proposition: Corollary contramap_compose `{Functor F} `{Contravariant G} : forall {X Y} (f : X -> Y), @fmap F _ (G Y) (G X) (@contramap G _ X Y f) = @contramap (F \o G) _ X Y f.
proof: Proof. reflexivity. Qed.
imports: Hask.Ltac Hask.Data.Functor FunctionalExtensionality