fact: Definition discrete_cat_nat_trans {C : precategory} {D : discrete_category} {F G : functor C D} (t : ∏ x : ob C, F x --> G x) : is_nat_trans F G t.
imports: UniMath.Foundations.PartA UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Setcategories UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.opp_precat