∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {P : C} ⦃f g : CategoryTheory.Over P⦄
  (motive : CategoryTheory.Abelian.PseudoEqual P f g → Prop) (h : CategoryTheory.Abelian.PseudoEqual P f g),
  (∀ (R : C) (p : R ⟶ f.left) (q : R ⟶ g.left) (ep : CategoryTheory.Epi p) (Eq : CategoryTheory.Epi q)
      (comm : CategoryTheory.CategoryStruct.comp p f.hom = CategoryTheory.CategoryStruct.comp q g.hom), motive ⋯) →
    motive h