Definition is_z_isomorphism_mor {C : precategory_data} {a b : C} {f : a --> b} (I : is_z_isomorphism f) : b --> a := pr1 I.
Require Import UniMath.Foundations.PartA. Require Import UniMath.Foundations.Propositions. Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.CategoryTheory.Core.Categories.