∀ {C : Type u₁} {inst : CategoryTheory.Category.{v₁, u₁} C} {inst_1 : CategoryTheory.MonoidalCategory C}
  {inst_2 : CategoryTheory.BraidedCategory C} (X : C) {inst_3 : CategoryTheory.ComonObj X}
  [self : CategoryTheory.IsCommComonObj X],
  CategoryTheory.CategoryStruct.comp CategoryTheory.ComonObj.comul (β_ X X).hom = CategoryTheory.ComonObj.comul