fact: Definition isaprop_associator_nat {C : category} {tu : tensor_unit C} (α : associator_data tu) : isaprop (associator_nat α).
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Isos