Definition CokernelOutPaths_is_iso_mor {x y : C} {f f' : x --> y} (e : f = f') (CK1 : Cokernel Z f) (CK2 : Cokernel Z f') : CK1 --> CK2. Proof. induction e. use CokernelOut. - use CokernelArrow. - use CokernelCompZero. Defined.
Require Import UniMath.Foundations.PartD. Require Import UniMath.Foundations.Propositions. Require Import UniMath.Foundations.Sets. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Epis. Require Import UniMath.CategoryTheory.Limits.Coequalizers. Require Import UniMath.CategoryTheory.Limits.Zero. - exact (ZeroArrowFrom w). - intros y X. cbn in X. use ArrowsFromZero.