Lemma nat_z_iso_id {C D:category} (F: C ⟶ D): nat_z_iso F F. Proof. apply (make_nat_z_iso F F (nat_trans_id F)). intro c. exists (identity (F c)). split; apply id_left. 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.TransportMorphisms. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.Univalence.