proposition: Lemma functor_opp_identity {C : precategory} (hsC : has_homsets C) : functor_opp (functor_identity C) = functor_identity C^op.
proof: Proof. apply (functor_eq _ _ (has_homsets_opp hsC)); trivial. 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