Module

AlgebraicExtensionUniqueness.lean

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

Uniqueness over an algebraic extension of a Henselian valued field

The integral closure is an actual valuation ring. Every extension valuation has this ring of integers, so any two extension valuations are equivalent.

Declarations

ValuationTheory.Henselian.valuationSubring_eq_integralClosure_of_henselianRing

The valuation ring of any algebraic extension valuation is the actual integral closure of the Henselian base valuation ring.

Source context 2 commands

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

namespace ValuationTheory.Henselian
variable {K L : Type*} [Field K] [Field L] [Algebra K L] [Algebra.IsAlgebraic K L]
  (V : ValuationSubring K) [HenselianRing V (IsLocalRing.maximalIdeal V)]
theorem valuationSubring_eq_integralClosure_of_henselianRing
    {Γ : Type*} [LinearOrderedCommGroupWithZero Γ]
    (w : _root_.Valuation L Γ) [V.valuation.HasExtension w] :
    w.valuationSubring.toSubring = (integralClosure V L).toSubring
ValuationTheory.Henselian.valuationSubring_eq_of_henselianRing

Extension valuations over a Henselian base have the same valuation ring.

Source context 2 commands

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

namespace ValuationTheory.Henselian
variable {K L : Type*} [Field K] [Field L] [Algebra K L] [Algebra.IsAlgebraic K L]
  (V : ValuationSubring K) [HenselianRing V (IsLocalRing.maximalIdeal V)]
theorem valuationSubring_eq_of_henselianRing
    {Γ₁ Γ₂ : Type*} [LinearOrderedCommGroupWithZero Γ₁]
    [LinearOrderedCommGroupWithZero Γ₂]
    (w₁ : _root_.Valuation L Γ₁) (w₂ : _root_.Valuation L Γ₂)
    [V.valuation.HasExtension w₁] [V.valuation.HasExtension w₂] :
    w₁.valuationSubring = w₂.valuationSubring