proposition: Lemma REL_precategory_has_homsets : has_homsets REL_precategory.
proof: Proof. exact (λ _ _, isaset_set_fun_space (pr1 _) (_ ,, isaset_set_fun_space _ (_ ,, isasethProp))). 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