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Mathlib.RingTheory.GradedAlgebra.FiniteType

Graded rings of finite type #

We show that graded rings of finite type (over the 0-th component) are generated by homogeneous elements of positive degree.

theorem GradedAlgebra.exists_finset_adjoin_eq_top_and_homogeneous {S : Type u_1} {σ : Type u_2} {ι : Type u_3} [DecidableEq ι] [AddCommMonoid ι] [CommRing S] [SetLike σ S] [AddSubgroupClass σ S] (𝒜 : ισ) [GradedRing 𝒜] [Algebra.FiniteType (↥(𝒜 0)) S] :
∃ (s : Finset S), Algebra.adjoin (𝒜 0) s = is, SetLike.IsHomogeneousElem 𝒜 i
theorem GradedAlgebra.exists_finset_adjoin_eq_top_and_homogeneous_ne_zero {S : Type u_1} {σ : Type u_2} {ι : Type u_3} [DecidableEq ι] [AddCommMonoid ι] [CommRing S] [SetLike σ S] [AddSubgroupClass σ S] (𝒜 : ισ) [GradedRing 𝒜] [Algebra.FiniteType (↥(𝒜 0)) S] :
∃ (s : Finset S), Algebra.adjoin (𝒜 0) s = is, ∃ (n : ι), n 0 i 𝒜 n