∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] (X : C) [inst_1 : CategoryTheory.Limits.HasBinaryCoproducts C],
  (CategoryTheory.algebraEquivUnder X).counitIso =
    CategoryTheory.NatIso.ofComponents
      (fun f =>
        CategoryTheory.Under.isoMk
          (CategoryTheory.Iso.refl
            (((CategoryTheory.underToAlgebra X).comp (CategoryTheory.algebraToUnder X)).obj f).right)
          ⋯)
      ⋯