Lemma is_z_iso_rassociator {a b c d : C} (f : hom_precategory a b) (g : hom_precategory b c) (h : hom_precategory c d) : is_z_isomorphism (rassociator f g h : (hom_precategory a d) ⟦ (f · g) · h, f · (g · h) ⟧). Proof. exists (lassociator f g h). split. - apply rassociator_lassociator. - apply lassociator_rassociator. 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.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.PrecategoryBinProduct.