∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {X Y : C} (f : X ⟶ Y)
  [inst_1 : CategoryTheory.IsSplitEpi f]
  (s :
    CategoryTheory.Limits.Cofork (CategoryTheory.CategoryStruct.id X)
      (CategoryTheory.CategoryStruct.comp f (CategoryTheory.section_ f))),
  CategoryTheory.CategoryStruct.comp (CategoryTheory.Limits.coconeOfIsSplitEpi f).π
      (CategoryTheory.CategoryStruct.comp (CategoryTheory.section_ f) s.π) =
    s.π