∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] (X : C) {D : Type u₂}
  [inst_1 : CategoryTheory.Category.{v₂, u₂} D] (e : C ≌ D),
  (CategoryTheory.MonoOver.congr X e).counitIso =
    CategoryTheory.NatIso.ofComponents (fun Y => CategoryTheory.MonoOver.isoMk (e.counitIso.app Y.obj.left) ⋯) ⋯