proposition: Lemma isaset_nat_trans {C C' : precategory_data} (hs: has_homsets C') (F F' : functor_data C C') : isaset (nat_trans F F').
proof: Proof. apply (isofhleveltotal2 2). + apply impred; intro t; apply hs. + intro x; apply isasetaprop, isaprop_is_nat_trans, hs. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.TransportMorphisms UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Univalence