fact: Definition nat_trans_ax {C C' : precategory_data} {F F' : functor_data C C'} (a : nat_trans F F') : ∏ (x x' : ob C)(f : x --> x'), #F f · a x' = a x · #F' f := pr2 a.
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