proposition: Lemma opp_opp_precat (C : precategory) (hs : has_homsets C) : C = C^op^op.
proof: Proof. use total2_paths_f. - apply opp_opp_precat_data. - apply (isaprop_is_precategory _ hs). Qed.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.FunctorCategory