fact: Definition rassociator_transf (a b c d : C) : precategory_binproduct_assoc (hom a b) (hom b c) (hom c d) ∙ pair_functor hcomp_functor (functor_identity _) ∙ hcomp_functor ⟹ pair_functor (functor_identity _) hcomp_functor ∙ hcomp_functor := rassociator_fun,, rassociator_fun_natural.
imports: UniMath.Tactics.EnsureStructuredProofs UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.PrecategoryBinProduct