OAI/Algebra/DepthFive/OperatorExponentBidegree.lean

GitHub source file

4 declarations, 0 contain sorry, 0 declared as axioms

Degree and validity of the natural exponent produced by a mixed monomial operator.

  1. theorem OAI.Problem335.bidegreeWeight_derivExponent line 15

    Source documentation

    Filtering to derivative variables retains precisely the first bidegree.

    theorem bidegreeWeight_derivExponent (isV : σ → Bool) (d : σ →₀ ℕ) :
        Finsupp.weight (bidegreeWeight isV) (derivExponent isV d) =
          ((Finsupp.weight (bidegreeWeight isV) d).1, 0) := by
    …

    Mentions: OAI.Problem335.bidegreeWeight, OAI.Problem335.derivExponent

  2. theorem OAI.Problem335.bidegreeWeight_mulExponent line 33

    Source documentation

    Filtering to multiplication variables retains precisely the second bidegree.

    theorem bidegreeWeight_mulExponent (isV : σ → Bool) (d : σ →₀ ℕ) :
        Finsupp.weight (bidegreeWeight isV) (mulExponent isV d) =
          (0, (Finsupp.weight (bidegreeWeight isV) d).2) := by
    …

    Mentions: OAI.Problem335.bidegreeWeight, OAI.Problem335.mulExponent

  3. theorem OAI.Problem335.bidegree_le_of_derivExponent_le line 51

    Source documentation

    Availability of every derivative implies availability of the total derivative degree.

    theorem bidegree_le_of_derivExponent_le (isV : σ → Bool) (d e : σ →₀ ℕ)
        {k m a b : ℕ} (hd : Finsupp.weight (bidegreeWeight isV) d = (k,m))
        (he : Finsupp.weight (bidegreeWeight isV) e = (a,b))
        (hle : derivExponent isV d ≤ e) : k ≤ a := by
    …

    Mentions: OAI.Problem335.bidegreeWeight, OAI.Problem335.derivExponent

  4. theorem OAI.Problem335.bidegreeWeight_operator_target line 64

    Source documentation

    A valid monomial action has a natural output exponent in exactly the required finite bidegree fiber, without any coefficient-field assumptions.

    theorem bidegreeWeight_operator_target (isV : σ → Bool) (d e : σ →₀ ℕ)
        {k m a b : ℕ} (hd : Finsupp.weight (bidegreeWeight isV) d = (k,m))
        (he : Finsupp.weight (bidegreeWeight isV) e = (a,b))
        (hle : derivExponent isV d ≤ e) :
        Finsupp.weight (bidegreeWeight isV)
          (e - derivExponent isV d + mulExponent isV d) = (a-k,b+m) := by
    …

    Mentions: OAI.Problem335.bidegreeWeight, OAI.Problem335.derivExponent, OAI.Problem335.mulExponent