proposition: Theorem coyo_to `{FunctorLaws f} : forall a (x : f a), lowerCoyoneda (liftCoyoneda x) = x.
proof: Proof. intros a x. unfold lowerCoyoneda, liftCoyoneda. rewrite fmap_id. reflexivity. Qed.
imports: Hask.Prelude Hask.Ltac Hask.Data.Functor.Identity Hask.Data.Functor.Kan Hask.Control.Monad FunctionalExtensionality FunctionalExtensionality