Lemma isaprop_isEqualizer {x y z : C} (f g : y --> z) (e : x --> y) (H : e · f = e · g) : isaprop (isEqualizer f g e H). Proof. repeat (apply impred; intro). apply isapropiscontr. 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.