∀ {A : Type u_1} {σ : Type u_2} [inst : CommRing A] [inst_1 : SetLike σ A] [inst_2 : AddSubmonoidClass σ A] (𝒜 : ℕ → σ)
  [inst_3 : GradedRing 𝒜] (t : Set (ProjectiveSpectrum 𝒜)),
  ProjectiveSpectrum.vanishingIdeal (closure t) = ProjectiveSpectrum.vanishingIdeal t