∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.MonoidalCategory C]
  [inst_2 : CategoryTheory.MarkovCategory C] (X : C) (f : X ⟶ CategoryTheory.MonoidalCategoryStruct.tensorUnit C),
  f = CategoryTheory.ComonObj.counit