Definition slice_to_PreShv_ob_is_nat {X Y : PreShv C / P} (F : X --> Y) : is_nat_trans (slice_to_PreShv_ob X : functor _ _) (slice_to_PreShv_ob Y : functor _ _) (slice_to_PreShv_ob_nat F).
Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.FunctorCategory. Require Import