Module

DivisionBounds.lean

Nyll.ValuedFieldTheory.Valuation.Henselian.Factorization.DivisionBounds
2 declarations indexed from sourceView source ↗

degree bounds for the division remainder

This file supplies the degree estimate for the remainder in the coefficientwise Hensel correction step. It removes the later need to assume separately that the residue of the remainder has small degree.

Declarations

AlgebraicNumberTheory.Valuations.henselFactorization_remainder_natDegree_le_of_degree_lt

the remainder estimate before reducing coefficients.

Source context 4 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open scoped Polynomial
namespace AlgebraicNumberTheory
namespace Valuations
theorem henselFactorization_remainder_natDegree_le_of_degree_lt
    {R : Type*} [CommRing R] {g0 p : R[X]} {m : ℕ}
    (hg0nat : g0.natDegree = m) (hpdeg : p.degree < g0.degree) :
    p.natDegree ≤ m
AlgebraicNumberTheory.Valuations.henselFactorization_residue_remainder_natDegree_le_of_degree_lt

the remainder estimate in residue-degree form: if the division remainder has degree strictly smaller than g0, and g0 has natural degree m, then the residue of the remainder has natural degree at most m.

Source context 4 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
open scoped Polynomial
namespace AlgebraicNumberTheory
namespace Valuations
theorem henselFactorization_residue_remainder_natDegree_le_of_degree_lt
    {R : Type*} [CommRing R] [IsLocalRing R]
    {g0 p : R[X]} {m : ℕ}
    (hg0nat : g0.natDegree = m) (hpdeg : p.degree < g0.degree) :
    (p.map (IsLocalRing.residue R)).natDegree ≤ m