proposition: Lemma bifunctor_comp_right {A B C : category} (F : A ⊠ B ⟶ C) {a : A} {b b' b'' : B} (f : b --> b') (g : b' --> b'') : #F (identity a #, f · g) = #F (identity _ #, f) · #F (identity _ #, g).
proof: Proof. rewrite <- (functor_comp F). change ((?x #, ?y) · (?z #, ?w)) with (x · z #, y · w). rewrite id_left. reflexivity. Qed.
imports: UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Monoidal.Categories UniMath.CategoryTheory.PrecategoryBinProduct UniMath.CategoryTheory.Core.Isos