Lemma isEqualizerUnderIso : isEqualizer f' g' e' p'. Proof. intros w h q. use iscontraprop1. - apply isEqualizerUnderIso_uvp_uniqueness. - exact (isEqualizerUnderIso_uvp_existence q). 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.Monics. Require Import UniMath.CategoryTheory.Retracts.