∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] (G : CategoryTheory.Comonad C) (X : G.Coalgebra) (Y : C)
  (f : G.forget.obj X ⟶ Y),
  CategoryTheory.CategoryStruct.comp X.a (G.map (CategoryTheory.CategoryStruct.comp X.a (G.map f))) =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.CategoryStruct.comp X.a (G.map f)) (G.cofree.obj Y).a