Definition invertible_relation_is_functional {X Y : hSet} {r : bin_hrel X Y} (p : is_z_isomorphism (C := REL) r) : ∏ (x : X) (y1 y2 : Y), r x y1 -> r x y2 -> y1 = y2.
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.