Module

LocalFieldRangeRestriction.lean

Nyll.ValuedFieldTheory.LocalField.DiscreteValuationField.ValuationSubringUnits.LocalFieldRangeRestriction
3 declarations indexed from sourceView source ↗

Multiplicative-range restriction for local fields

This file packages range restriction as a LocalField and exposes the properness and completeness of the resulting topology.

Declarations

LocalFieldTheory.DiscreteValuationField.LocalField.mrangeRestrict

A local-field package with its chosen valuation restricted to the actual multiplicative range.

Source context 7 commands

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

noncomputable section
universe u v
open scoped Valued
namespace LocalFieldTheory.DiscreteValuationField
open ValuationTheory.DiscreteValuationField
namespace LocalField
variable {K : Type u} [Field K]
def mrangeRestrict (F : LocalField.{u, v} K) :
    LocalField.{u, v} K
LocalFieldTheory.DiscreteValuationField.LocalField.mrangeRestrict_properSpace

The range-restricted topology attached to a local-field package is proper.

Source context 7 commands

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

noncomputable section
universe u v
open scoped Valued
namespace LocalFieldTheory.DiscreteValuationField
open ValuationTheory.DiscreteValuationField
namespace LocalField
variable {K : Type u} [Field K]
theorem mrangeRestrict_properSpace
    (F : LocalField.{u, v} K) :
    letI : Valued K
        (MonoidHom.mrange
          F.toCompleteDVF.valuation.toMonoidWithZeroHom) :=
      (CompleteDVF.mrangeRestrictValued F.toCompleteDVF)
    letI : NontriviallyNormedField K :=
      (CompleteDVF.mrangeRestrict_nontriviallyNormedField F.toCompleteDVF)
    ProperSpace K := by
  exact
    (CompleteDVF.mrangeRestrict_properSpace_of_residueField_finite F.toCompleteDVF)
LocalFieldTheory.DiscreteValuationField.LocalField.mrangeRestrict_completeSpace

The range-restricted topology attached to a local-field package is complete.

Source context 7 commands

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

noncomputable section
universe u v
open scoped Valued
namespace LocalFieldTheory.DiscreteValuationField
open ValuationTheory.DiscreteValuationField
namespace LocalField
variable {K : Type u} [Field K]
theorem mrangeRestrict_completeSpace
    (F : LocalField.{u, v} K) :
    letI : Valued K
        (MonoidHom.mrange
          F.toCompleteDVF.valuation.toMonoidWithZeroHom) :=
      (CompleteDVF.mrangeRestrictValued F.toCompleteDVF)
    letI : NontriviallyNormedField K :=
      (CompleteDVF.mrangeRestrict_nontriviallyNormedField F.toCompleteDVF)
    CompleteSpace K := by
  exact
    (CompleteDVF.mrangeRestrict_completeSpace_of_residueField_finite F.toCompleteDVF)