OAI/NumberTheory/Ostmann/Arithmetic/ArithmeticLines.lean

GitHub source file

9 declarations, 0 contain sorry, 0 declared as axioms

Exact line counts in the ideal giant residues

  1. def OAI.Ostmann.unitLineEquiv line 16

    Source documentation

    A feasible line on two unit coordinates has one point for each second coordinate.

    def unitLineEquiv {G : Type*} [CommGroup G] (a b : G) :
        {xy : G × G // a * xy.1 = b * xy.2} ≃ G where
    …
  2. theorem OAI.Ostmann.card_unitLine line 29
  3. def OAI.Ostmann.externalLineEquiv line 34

    Source documentation

    An external integer coordinate is unrestricted; the second coordinate is still a unit.

    noncomputable def externalLineEquiv {p : ℕ} [Fact p.Prime]
        (a : (ZMod p)ˣ) (b : ZMod p) :
        {xy : ZMod p × (ZMod p)ˣ // (a : ZMod p) * xy.1 = b * xy.2} ≃ (ZMod p)ˣ where
    …
  4. theorem OAI.Ostmann.card_externalLine line 50
  5. theorem OAI.Ostmann.unitLine_probability line 56
  6. theorem OAI.Ostmann.externalLine_probability line 64
  7. theorem OAI.Ostmann.independent_lines_no_unit_solution line 72
  8. theorem OAI.Ostmann.line_zero_first_coefficient line 79
  9. theorem OAI.Ostmann.dependent_lines_iff line 84

    Source documentation

    Vanishing two-by-two minors reduce all occurrence tests to one nonzero row.

    theorem dependent_lines_iff {K I : Type*} [Field K]
        (a b : I → K) (i : I) (ha : a i ≠ 0)
        (hdet : ∀ j, a i * b j - b i * a j = 0) (x y : K) :
        (∀ j, a j * x + b j * y = 0) ↔ a i * x + b i * y = 0 := by
    …