fact: Definition laxassociator_to_associator_nat_left {C : category} {tu : tensor_unit C} (α : laxassociator tu) : associator_nat_leftwhisker α := pr12 α.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Monoidal.WhiskeredBifunctors UniMath.CategoryTheory.Monoidal.Categories