fact: Definition nat_trans {C C' : precategory_data} (F F' : functor_data C C') : UU := total2 (fun t : nat_trans_data F F' => is_nat_trans F F' t).
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