Definition associator_2mor {C : prebicategory_data} {a b c d : C} (f : a -1-> b) (g : b -1-> c) (h : c -1-> d) : (f ;1; (g ;1; h)) -2-> ((f ;1; g) ;1; h) := associator_trans a b c d (make_catbinprod f (make_catbinprod g h)).
Require Import UniMath.Foundations.PartD. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Univalence. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.PrecategoryBinProduct. Require Import UniMath.CategoryTheory.Categories.StandardCategories. Require Import UniMath.CategoryTheory.HorizontalComposition. Require Import UniMath.CategoryTheory.Equivalences.Core.