Lemma isaprop_is_nat_trans (C C' : precategory_data) (hs: has_homsets C') (F F' : functor_data C C') (t : nat_trans_data F F'): isaprop (is_nat_trans F F' t). Proof. repeat (apply impred; intro). apply hs. Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.TransportMorphisms. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.Univalence.