OAI/Algebra/Finitistic/Encoding/QuadraticCoefficients.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

  1. abbrev OAI.LittleFinitistic.QuadraticPresentation.Term line 10
  2. def OAI.LittleFinitistic.QuadraticPresentation.term line 12
  3. theorem OAI.LittleFinitistic.QuadraticPresentation.degreeLE_two_eq_span line 19

    Source documentation

    The degree bound is exactly the span of constants, generators, and ordered products of two generators. The two factors are never commuted.

    theorem degreeLE_two_eq_span :
        degreeLE R α 2 = Submodule.span R (Set.range (term R α)) := by
    …

    Mentions: OAI.LittleFinitistic.QuadraticPresentation.degreeLE, OAI.LittleFinitistic.QuadraticPresentation.term

  4. def OAI.LittleFinitistic.QuadraticPresentation.coefficientPolynomial line 42

    Source documentation

    Finite coefficient form, suitable for the source's homogenization rule.

    def coefficientPolynomial [Fintype α] (c : R) (l : α → R) (q : α → α → R) :
        FreeAlgebra R α :=
    …
  5. theorem OAI.LittleFinitistic.QuadraticPresentation.exists_coefficients line 48
  6. theorem OAI.LittleFinitistic.QuadraticPresentation.coefficientPolynomial_degree line 58
  7. theorem OAI.LittleFinitistic.QuadraticPresentation.degreeLE_two_iff_coefficients line 71

    Source documentation

    An exact characterization; the degree predicate hides no higher terms.

    theorem degreeLE_two_iff_coefficients [Fintype α] (p : FreeAlgebra R α) :
        p ∈ degreeLE R α 2 ↔
          ∃ (c : R) (l : α → R) (q : α → α → R), coefficientPolynomial R α c l q = p := by
    …

    Mentions: OAI.LittleFinitistic.QuadraticPresentation.degreeLE, OAI.LittleFinitistic.QuadraticPresentation.coefficientPolynomial

  8. theorem OAI.LittleFinitistic.QuadraticPresentation.relation_coefficients line 80

    Source documentation

    Every new quadratic relation has explicit constant, linear, and ordered quadratic coefficients, with a simultaneous choice for the whole finite family.

    theorem relation_coefficients [Finite α] {κ : Type*} (p : κ → FreeAlgebra R α) (N : ℕ) :
        letI := Fintype.ofFinite (Letter α N)
    …

    Mentions: OAI.LittleFinitistic.QuadraticPresentation.Letter