no goals
R : Type u_2
A : Type u_1
inst✝³ : CommSemiring R
inst✝² : CommRing A
inst✝¹ : Algebra R A
𝒜 : ℕ → Submodule R A
inst✝ : GradedAlgebra 𝒜
Z : Set (ProjectiveSpectrum 𝒜)
⊢ IsClosed Z ↔ ∃ s, Z = zeroLocus 𝒜 s
rw [← isOpen_compl_iff, isOpen_iff, compl_compl]