Definition z_iso_in_SET_to_z_iso_in_REL {X Y : HSET} (i : z_iso (C := HSET) X Y) : z_iso (C := REL) X Y := _ ,, invertiblefunction_to_invertiblerelation (pr2 i).
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.Categories.HSET.All.