Definition is_z_isomorphism_comp {C : precategory} {a b c : C} {f1 : a --> b} {f2 : b --> c} (H1 : is_z_isomorphism f1) (H2 : is_z_isomorphism f2) : is_z_isomorphism (f1 · f2). Proof. use make_is_z_isomorphism. - exact (is_z_isomorphism_mor H2 · is_z_isomorphism_mor H1). - exact (is_inverse_in_precat_comp H1 H2). Defined.
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.