proposition: Lemma rassociator_lassociator_CAT {C D E F : category} (X : [C, D]) (Y : [D, E]) (Z : [E, F]) : rassociator_CAT X Y Z · lassociator_CAT _ _ _ = id2_CAT _.
proof: Proof. apply (nat_trans_eq F); intro c. apply id_right. Qed.
imports: UniMath.Foundations.PartD UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.whiskering