proposition: Lemma mappend_assoc_sym : mappend ∘ bimap id mappend ≈ mappend ∘ bimap mappend id ∘ (tensor_assoc ⁻¹).
proof: Proof. rewrite mappend_assoc. rewrite <- comp_assoc. rewrite iso_to_from. cat. Qed.
imports: Category.Lib Category.Theory.Category Category.Theory.Isomorphism Category.Theory.Functor Category.Functor.Bifunctor Category.Structure.Terminal Category.Structure.Cartesian Category.Structure.Monoidal Category.Structure.Monoidal.Internal.Product Category.Structure.Cartesian.Closed Category.Instance.Sets