fact: Definition laxleftunitor_to_lunitor_nat {C : category} {tu : tensor_unit C} (lu : laxleftunitor tu) : leftunitor_nat lu := pr2 lu.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Monoidal.WhiskeredBifunctors UniMath.CategoryTheory.Monoidal.Categories