proposition: Lemma is_univalent_REL : is_univalent REL.
proof: Proof. intros X Y. use weqhomot. - exact (bin_hrel_z_iso_equiv_hset_z_iso X Y ∘ make_weq _ (is_univalent_HSET X Y))%weq. - intro p ; induction p. use (z_iso_eq (C := REL)). do 2 (apply funextsec ; intro). apply idpath. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Categories.HSET.All