∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] (P : CategoryTheory.ObjectProperty C)
  [P.IsClosedUnderIsomorphisms] [CategoryTheory.ObjectProperty.EssentiallySmall.{w, v, u} P],
  ∃ P₀, ∃ (_ : CategoryTheory.ObjectProperty.Small.{w, v, u} P₀), P = P₀.isoClosure