proposition: Lemma isaprop_pentagon {C : category} {tu : tensor_unit C} (ua : unitors_associator tu) : isaprop (pentagon ua).
proof: Proof. repeat (apply impred_isaprop ; intro). apply homset_property. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Isos