OAI/AlgebraicGeometry/PlaneCurves/RelationIdeals.lean
11 declarations, 0 contain sorry, 0 declared as axioms
Polynomial relation ideals, generators, and prime relations
- def
OAI.Nagata.Workers.W25.polynomialRelationIdealline 19Source documentation
Every relation is tested by evaluation at every point of the punctured plane.
def polynomialRelationIdeal (s : Fin 3 → ℂ → ℂ) : Ideal (MvPolynomial (Fin 3) ℂ) := … - theorem
OAI.Nagata.Workers.W25.mem_polynomialRelationIdealline 23 - theorem
OAI.Nagata.Workers.W25.one_not_mem_polynomialRelationIdealline 31Source documentation
The constant one never vanishes, since the punctured plane contains one.
theorem one_not_mem_polynomialRelationIdeal (s : Fin 3 → ℂ → ℂ) : (1 : MvPolynomial (Fin 3) ℂ) ∉ polynomialRelationIdeal s := by … - theorem
OAI.Nagata.Workers.W25.polynomialRelationIdeal_ne_topline 38Source documentation
Properness is unconditional and does not assume an algebraic image theorem.
theorem polynomialRelationIdeal_ne_top (s : Fin 3 → ℂ → ℂ) : polynomialRelationIdeal s ≠ ⊤ := by … - theorem
OAI.Nagata.Workers.W25.span_le_polynomialRelationIdealline 44Source documentation
Relation-ideal containment is exactly vanishing of each chosen generator.
theorem span_le_polynomialRelationIdeal (s : Fin 3 → ℂ → ℂ) (E : Set (MvPolynomial (Fin 3) ℂ)) : Ideal.span E ≤ polynomialRelationIdeal s ↔ ∀ P ∈ E, ∀ z : ℂ, z ≠ 0 → MvPolynomial.eval (fun i => s i z) P = 0 := by … - theorem
OAI.Nagata.Workers.W25.relation_generator_dvd_iffline 64 - theorem
OAI.Nagata.Workers.W25.exists_eval_ne_zero_of_not_dvd_relation_generatorline 71 - theorem
OAI.Nagata.Workers.W25.polynomialRelationIdeal_isPrimeline 95Source documentation
The identity principle on the connected punctured plane makes its polynomial relation ideal prime. Holomorphicity is an explicit, ordinary function hypothesis.
theorem polynomialRelationIdeal_isPrime (s : Fin 3 → ℂ → ℂ) (hs : ∀ i, DifferentiableOn ℂ (s i) {z : ℂ | z ≠ 0}) : (polynomialRelationIdeal s).IsPrime := by … - theorem
OAI.Nagata.Workers.W25.cubicSectionRelationIdeal_isPrimeline 106Source documentation
Specialization to actual degree-three automorphic sections, with their holomorphicity derived from membership in the concrete section space.
theorem cubicSectionRelationIdeal_isPrime {τ γ : ℂ} (b : Fin 3 → Nagata.W08.automorphicSections τ 3 γ) : (polynomialRelationIdeal (fun i => (b i).val)).IsPrime := …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.Workers.W25.polynomialRelationIdeal
- theorem
OAI.Nagata.Workers.W25.exists_cubic_mem_relationIdealline 114Source documentation
The actual cubic relation belongs to the relation ideal. Only the stated finite-dimensional degree-nine section input is used here.
theorem exists_cubic_mem_relationIdeal {τ γ : ℂ} (b : Fin 3 → Nagata.W08.automorphicSections τ 3 γ) [Module.Finite ℂ (Nagata.W08.automorphicSections τ 9 (γ ^ 3))] (hdim : Module.finrank ℂ (Nagata.W08.automorphicSections τ 9 (γ ^ 3)) ≤ 9) : ∃ P : MvPolynomial (Fin 3) ℂ, P ≠ 0 ∧ P.IsHomogeneous 3 ∧ P ∈ polynomialRelationIdeal (fun i => (b i).val) := by …Mentions: OAI.Nagata.W08.automorphicSections, OAI.Nagata.Workers.W25.polynomialRelationIdeal
- theorem
OAI.Nagata.Workers.W25.basis_pair_linear_relation_trivialline 137