proposition: Lemma cat_of_elems_on_nat_trans_is_functor (α : X ⟹ Y) : is_functor (cat_of_elems_on_nat_trans_data α).
proof: Proof. split. - now intros a; apply cat_of_elems_mor_eq. - now intros a b c f g; apply cat_of_elems_mor_eq. Qed.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.Categories.HSET.Core UniMath.CategoryTheory.opp_precat UniMath.CategoryTheory.Presheaf