proposition: Theorem triangle_identity_right {x y} : id ⨂ unit_right << x ⨂ (y ⨂ I) ~~> x ⨂ y >> unit_right ∘ tensor_assoc⁻¹.
proof: Proof. pose proof (@bimap_unit_right_id x y I). normal. apply tensor_id_right_inj in X. assumption. Qed.
imports: Category.Lib Category.Theory.Category Category.Theory.Isomorphism Category.Theory.Functor Category.Functor.Bifunctor Category.Structure.Monoidal