Weighted monic relations yield eventual bounded representatives
ProvedOAI.PiExponent.FormalInterpolation.weighted_monic_relations_eventual_representativesWeighted monic relations in a power of an ideal produce eventual bounded-support representatives modulo every power of the ideal, with any degree rate above the relations' rate.
Let be an ideal, rational degree weights. Suppose that for some and positive integers there are polynomials such that every exponent in the support of the monic relation satisfies
and the relation degrees obey a rate budget
for some rational . Then for every rational rate there is a threshold such that every polynomial has, for all , a representative with
The proof is weighted monic division: a monomial whose weighted degree exceeds has floor cost exceeding , so a product of relations gives an element of agreeing with on its leading monomial and strictly decreasing the weighted degree; well-foundedness of weighted-degree descent then yields remainders supported below weighted degree , and linearity extends the construction from monomials to all polynomials.
import Definitions.Def_OAI_PiExponent_WeightedIdealCurveCriterion open scoped BigOperators open OAI.PiExponent.FormalInterpolation
theorem OAI.PiExponent.FormalInterpolation.weighted_monic_relations_eventual_representatives
{d : Nat} (I : Ideal (MvPolynomial (Fin d) Complex))
(w : Fin d → Rat) (hw : ∀ i, 0 < (w i : Real))
(k : Nat) (hk : 0 < k)
(b : Fin d → Nat) (hb : ∀ i, 0 < b i)
(F : Fin d → MvPolynomial (Fin d) Complex)
(hF : ∀ i, F i ∈ I ^ k)
(hbelow : ∀ i, ∀ v ∈ (MvPolynomial.X i ^ b i - F i).support,
(∑ j, (w j : Real) * (v j : Real)) < (w i : Real) * (b i : Real))
(a delta : Rat) (ha0 : 0 < a) (ha : a < delta)
(hbudget : ∀ i, (w i : Real) * (b i : Real) ≤ (k : Real) * (a : Real)) :
∃ n₀ : Nat, ∀ n : Nat, n₀ ≤ n →
∀ p : MvPolynomial (Fin d) Complex,
∃ q : MvPolynomial (Fin d) Complex,
p - q ∈ I ^ n ∧
∀ u ∈ q.support,
∑ i, (w i : Real) * (u i : Real) ≤ (n : Real) * (delta : Real) := by
sorry