{σ : Type u_1} →
  {A : Type u} →
    [inst : CommRing A] →
      [inst_1 : SetLike σ A] →
        [inst_2 : AddSubgroupClass σ A] →
          (𝒜 : ℕ → σ) → [inst_3 : GradedRing 𝒜] → (AlgebraicGeometry.Proj 𝒜).AffineOpenCover