Definition α_functors_funcat_inv (X : [C, D]) (Y : [D, E]) (Z : [E, F]) : [C, F] ⟦functor_compose X (functor_compose Y Z), functor_compose (functor_compose X Y) Z⟧ := nat_trans_id ((X ∙ Y) ∙ Z).
Require Import UniMath.Foundations.PartD. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.FunctorCategory.