Lemma hcomp_identity_left {a b c : C} (f : C ⟦ a, b ⟧)(g1 g2 : C ⟦ b, c ⟧) (y : g1 ==> g2) : id2 f ⋆ y = lwhisker f y. Proof. unfold hcomp. rewrite id2_rwhisker. apply id2_left. Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.PrecategoryBinProduct.