OAI/AlgebraicGeometry/PlaneCurves/RelationIdeals.lean

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11 declarations, 0 contain sorry, 0 declared as axioms

Polynomial relation ideals, generators, and prime relations

  1. def OAI.Nagata.Workers.W25.polynomialRelationIdeal line 19

    Source 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) :=
    …
  2. theorem OAI.Nagata.Workers.W25.mem_polynomialRelationIdeal line 23
  3. theorem OAI.Nagata.Workers.W25.one_not_mem_polynomialRelationIdeal line 31

    Source 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
    …

    Mentions: OAI.Nagata.Workers.W25.polynomialRelationIdeal

  4. theorem OAI.Nagata.Workers.W25.polynomialRelationIdeal_ne_top line 38

    Source documentation

    Properness is unconditional and does not assume an algebraic image theorem.

    theorem polynomialRelationIdeal_ne_top (s : Fin 3 → ℂ → ℂ) :
        polynomialRelationIdeal s ≠ ⊤ := by
    …

    Mentions: OAI.Nagata.Workers.W25.polynomialRelationIdeal

  5. theorem OAI.Nagata.Workers.W25.span_le_polynomialRelationIdeal line 44

    Source 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
    …

    Mentions: OAI.Nagata.Workers.W25.polynomialRelationIdeal

  6. theorem OAI.Nagata.Workers.W25.relation_generator_dvd_iff line 64
  7. theorem OAI.Nagata.Workers.W25.exists_eval_ne_zero_of_not_dvd_relation_generator line 71
  8. theorem OAI.Nagata.Workers.W25.polynomialRelationIdeal_isPrime line 95

    Source 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
    …

    Mentions: OAI.Nagata.Workers.W25.polynomialRelationIdeal

  9. theorem OAI.Nagata.Workers.W25.cubicSectionRelationIdeal_isPrime line 106

    Source 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

  10. theorem OAI.Nagata.Workers.W25.exists_cubic_mem_relationIdeal line 114

    Source 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

  11. theorem OAI.Nagata.Workers.W25.basis_pair_linear_relation_trivial line 137