Lemma EqualizerOfIso_diagram_proof_pd_e : pr21 E = identity_z_iso E · (EqualizerArrow E · i) · pr12 i. Proof. apply pathsinv0 ; refine (assoc' _ _ _ @ _); refine (id_left _ @ _); refine (_ @ id_right _); refine (assoc' _ _ _ @ _); apply maponpaths; apply z_iso_inv_after_z_iso. Qed.
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.