∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.MonoidalCategory C]
  [inst_2 : CategoryTheory.BraidedCategory C] (X Y : C),
  (CategoryTheory.BraidedCategory.tensorLeftIsoTensorRight X).hom.app Y = (β_ X Y).hom