∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {X Y : C} {f : X ⟶ Y} (h : CategoryTheory.SplitEpi f),
  (CategoryTheory.CategoryStruct.comp f.op h.section_.op).unop = (CategoryTheory.CategoryStruct.id (Opposite.op Y)).unop