Lemma whisker_left_right {C : prebicategory} {a b c d : C} (f : a -1-> b) (g h : b -1-> c) (i : c -1-> d) (x : g -2-> h) : whisker_left f (whisker_right x i) ;v; associator_2mor f h i = associator_2mor f g i ;v; whisker_right (whisker_left f x) i. Proof. exact (associator_naturality (identity f) x (identity i)). Defined.
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.Univalence. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.PrecategoryBinProduct. Require Import UniMath.CategoryTheory.HorizontalComposition. Require Import UniMath.Bicategories.WkCatEnrichment.prebicategory. Require Import UniMath.Bicategories.WkCatEnrichment.whiskering. Require Import UniMath.Bicategories.Core.Bicat. Import Bicat.Notations. Require Import UniMath.Bicategories.WkCatEnrichment.Notations.