Module

Core.lean

Nyll.ValuedFieldTheory.LocalField.DiscreteValuationField.PrincipalUnits.Core
69 declarations indexed from sourceView source ↗

Develops quotients of valuation-ring units by higher principal units and compares their first layer with residue-field units.

Successive principal-unit quotients

Declarations

LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModOne_mk_eq_iff_residueUnitHom_eq

Characterizes QuotientGroup.mk' (higherPrincipalUnitGroup F 1) u = QuotientGroup.mk' (higherPrincipalUnitGroup F 1) v by the equivalent condition higherPrincipalUnitGroup.residueUnitHom F u = higherPrincipalUnitGroup.residueUnitHom F v.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem unitsModOne_mk_eq_iff_residueUnitHom_eq
    (u v : F.valuationSubringˣ) :
    QuotientGroup.mk' (higherPrincipalUnitGroup F 1) u =
        QuotientGroup.mk' (higherPrincipalUnitGroup F 1) v ↔
      higherPrincipalUnitGroup.residueUnitHom F u =
        higherPrincipalUnitGroup.residueUnitHom F v
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModOne_mk_eq_iff_residue_eq

Characterizes QuotientGroup.mk' (higherPrincipalUnitGroup F 1) u = QuotientGroup.mk' (higherPrincipalUnitGroup F 1) v by the equivalent condition F.residueMap (u : F.valuationSubring) = F.residueMap (v : F.valuationSubring).

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem unitsModOne_mk_eq_iff_residue_eq
    (u v : F.valuationSubringˣ) :
    QuotientGroup.mk' (higherPrincipalUnitGroup F 1) u =
        QuotientGroup.mk' (higherPrincipalUnitGroup F 1) v ↔
      F.residueMap (u : F.valuationSubring) =
        F.residueMap (v : F.valuationSubring)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientMaximalIdealPowRingEquivOfPreserves

A valuation-ring-preserving field automorphism induces a ring automorphism on every quotient O/m^n.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def quotientMaximalIdealPowRingEquivOfPreserves
    (e : K ≃+* K)
    (hmem :
      ∀ x : K,
        x ∈ F.valuation.valuationSubring ↔
          e x ∈ F.valuation.valuationSubring)
    (n : ℕ) :
    F.valuationSubring ⧸ F.maximalIdeal ^ n ≃+*
      F.valuationSubring ⧸ F.maximalIdeal ^ n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientMaximalIdealPowRingEquivOfPreserves_mk

Establishes the identity quotientMaximalIdealPowRingEquivOfPreserves F e hmem n (Ideal.Quotient.mk (F.maximalIdeal ^ n) x) = Ideal.Quotient.mk (F.maximalIdeal ^ n) (valuationSubringRingEquivOfPreserves F e hmem x).

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem quotientMaximalIdealPowRingEquivOfPreserves_mk
    (e : K ≃+* K)
    (hmem :
      ∀ x : K,
        x ∈ F.valuation.valuationSubring ↔
          e x ∈ F.valuation.valuationSubring)
    (n : ℕ) (x : F.valuationSubring) :
    quotientMaximalIdealPowRingEquivOfPreserves F e hmem n
        (Ideal.Quotient.mk (F.maximalIdeal ^ n) x) =
      Ideal.Quotient.mk (F.maximalIdeal ^ n)
        (valuationSubringRingEquivOfPreserves F e hmem x)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientUnitHom

Reduction of valuation-ring units modulo the n-th power of the maximal ideal.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def quotientUnitHom (n : ℕ) :
    F.valuationSubringˣ →*
      (F.valuationSubring ⧸ F.maximalIdeal ^ n)ˣ
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientUnitHom_apply

The defining evaluation formula for quotientUnitHom is ((higherPrincipalUnitGroup.quotientUnitHom F n u : (F.valuationSubring ⧸ F.maximalIdeal ^ n)ˣ) : F.valuationSubring ⧸ F.maximalIdeal ^ n) = Ideal.Quotient.mk (F.maximalIdeal ^ n) (u : F.valuationSubring).

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem quotientUnitHom_apply (n : ℕ) (u : F.valuationSubringˣ) :
    ((higherPrincipalUnitGroup.quotientUnitHom F n u :
        (F.valuationSubring ⧸ F.maximalIdeal ^ n)ˣ) :
      F.valuationSubring ⧸ F.maximalIdeal ^ n) =
      Ideal.Quotient.mk (F.maximalIdeal ^ n) (u : F.valuationSubring)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientUnitHom_valuationSubringUnitEquivOfPreserves

Compatibility between the induced action on O^*, the induced action on O/m^n, and reduction of units modulo m^n.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem quotientUnitHom_valuationSubringUnitEquivOfPreserves
    (e : K ≃+* K)
    (hmem :
      ∀ x : K,
        x ∈ F.valuation.valuationSubring ↔
          e x ∈ F.valuation.valuationSubring)
    (n : ℕ) (u : F.valuationSubringˣ) :
    Units.map
        (quotientMaximalIdealPowRingEquivOfPreserves F e hmem n).toMonoidHom
        (higherPrincipalUnitGroup.quotientUnitHom F n u) =
      higherPrincipalUnitGroup.quotientUnitHom F n
        (valuationSubringUnitEquivOfPreserves F e hmem u)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientUnitHom_ker_eq

The kernel of unit reduction modulo m^n is exactly the concrete principal-unit subgroup U^n.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem quotientUnitHom_ker_eq (n : ℕ) :
    (higherPrincipalUnitGroup.quotientUnitHom F n).ker =
      higherPrincipalUnitGroup F n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModHigherPrincipalUnitGroupEquivRange

First-isomorphism form of unit reduction modulo m^n: O^*/U^n is the range of the unit group of O/m^n.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def unitsModHigherPrincipalUnitGroupEquivRange (n : ℕ) :
    F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n ≃*
      (higherPrincipalUnitGroup.quotientUnitHom F n).range
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientUnitHom_surjective_of_pos

For n ≥ 1, every unit modulo m^n is the reduction of a valuation-ring unit.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem quotientUnitHom_surjective_of_pos {n : ℕ} (hn : 1 ≤ n) :
    Function.Surjective (higherPrincipalUnitGroup.quotientUnitHom F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModHigherPrincipalUnitGroupEquivQuotientUnits

The unit-quotient coordinate theorem, first unit-quotient form: O^*/U^n ≃ (O/m^n)^* for n ≥ 1.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def unitsModHigherPrincipalUnitGroupEquivQuotientUnits
    (n : ℕ) (hn : 1 ≤ n) :
    F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n ≃*
      (F.valuationSubring ⧸ F.maximalIdeal ^ n)ˣ
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.maximalIdeal_fg

The maximal ideal of a complete DVF valuation ring is finitely generated: it is generated by any uniformizer.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem maximalIdeal_fg :
    F.maximalIdeal.FG
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.finite_quotient_maximalIdeal_pow_of_finite_residue

If the residue field is finite, then every quotient by a power of the maximal ideal is finite.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem finite_quotient_maximalIdeal_pow_of_finite_residue
    [Finite F.residueField] (n : ℕ) :
    Finite (F.valuationSubring ⧸ F.maximalIdeal ^ n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.finite_unitsModHigherPrincipalUnitGroup_of_finite_residue

Finite-residue complete DVFs have finite unit quotients O^*/U^n.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem finite_unitsModHigherPrincipalUnitGroup_of_finite_residue
    [Finite F.residueField] (n : ℕ) :
    Finite (F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.quotientMaximalIdealPowFinite

The type in Finite (F.valuationSubring ⧸ F.maximalIdeal ^ n) is finite.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
instance quotientMaximalIdealPowFinite
    [Finite F.residueField] (n : ℕ) :
    Finite (F.valuationSubring ⧸ F.maximalIdeal ^ n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModHigherPrincipalUnitGroupFinite

The type in Finite (F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n) is finite.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
instance unitsModHigherPrincipalUnitGroupFinite
    [Finite F.residueField] (n : ℕ) :
    Finite (F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.card_unitsModHigherPrincipalUnitGroup_eq_quotientUnits

Cardinality form of O^*/U^n ≃ (O/m^n)^* for n ≥ 1 over a finite residue field. The finite instances are derived from the residue field before either natural cardinal is formed.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem card_unitsModHigherPrincipalUnitGroup_eq_quotientUnits
    [Finite F.residueField] (n : ℕ) (hn : 1 ≤ n) :
    Nat.card (F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n) =
      Nat.card ((F.valuationSubring ⧸ F.maximalIdeal ^ n)ˣ)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.finite_principalUnitSubquotient_of_finite_residue

Every concrete principal-unit subquotient is finite when the residue field is finite. It is identified with the range of the inclusion into the finite full unit quotient.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem finite_principalUnitSubquotient_of_finite_residue
    [Finite F.residueField] (m n : ℕ) :
    Finite (higherPrincipalUnitGroup F m ⧸
      (higherPrincipalUnitGroup F n).subgroupOf
        (higherPrincipalUnitGroup F m))
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSubquotientFinite

The type in Finite (higherPrincipalUnitGroup F m ⧸ (higherPrincipalUnitGroup F n).subgroupOf (higherPrincipalUnitGroup F m)) is finite.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
instance principalUnitSubquotientFinite
    [Finite F.residueField] (m n : ℕ) :
    Finite (higherPrincipalUnitGroup F m ⧸
      (higherPrincipalUnitGroup F n).subgroupOf
        (higherPrincipalUnitGroup F m))
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.toPrincipalUnitFiltration

The concrete principal-unit filtration as the abstract filtration API.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def toPrincipalUnitFiltration :
    AntitoneSubgroupFiltration F.valuationSubringˣ where
  subgroup := higherPrincipalUnitGroup F
  antitone := fun h => higherPrincipalUnitGroup.antitone F h
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.toPrincipalUnitFiltration_subgroup

Establishes the identity (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).subgroup n = higherPrincipalUnitGroup F n.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem toPrincipalUnitFiltration_subgroup (n : ℕ) :
    (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).subgroup n =
      higherPrincipalUnitGroup F n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.toPrincipalUnitFiltrationPrincipalUnitSubquotientFinite

The type in Finite ((higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitSubquotient m n) is finite.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
instance toPrincipalUnitFiltrationPrincipalUnitSubquotientFinite
    [Finite F.residueField] (m n : ℕ) :
    Finite
      ((higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitSubquotient
        m n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuot

The adjacent quotient U^n/U^(n+1) for the concrete complete-DVF principal-unit filtration.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuot (n : ℕ) : Type u
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotCommGroup

Equips the target with its canonical CommGroup structure, namely CommGroup (higherPrincipalUnitGroup.principalUnitSuccQuot F n).

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
instance principalUnitSuccQuotCommGroup (n : ℕ) :
    CommGroup (higherPrincipalUnitGroup.principalUnitSuccQuot F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotConcreteEquiv

Explicit access to the concrete quotient used to implement principalUnitSuccQuot.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotConcreteEquiv (n : ℕ) :
    higherPrincipalUnitGroup.principalUnitSuccQuot F n ≃*
      (higherPrincipalUnitGroup F n ⧸
        (higherPrincipalUnitGroup F (n + 1)).subgroupOf
          (higherPrincipalUnitGroup F n))
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotMk

The quotient map U^n → U^n/U^(n+1).

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotMk (n : ℕ) :
    higherPrincipalUnitGroup F n →*
      higherPrincipalUnitGroup.principalUnitSuccQuot F n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotConcreteEquiv_mk

Establishes the identity higherPrincipalUnitGroup.principalUnitSuccQuotConcreteEquiv F n (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u) = QuotientGroup.mk u.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotConcreteEquiv_mk (n : ℕ)
    (u : higherPrincipalUnitGroup F n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotConcreteEquiv F n
        (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u) =
      QuotientGroup.mk u
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotMk_surjective

The specified map is surjective: Function.Surjective (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n).

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotMk_surjective (n : ℕ) :
    Function.Surjective (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuot.inductionOn

Eliminate an adjacent principal-unit quotient through its canonical representatives.

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuot.inductionOn
    (n : ℕ)
    {motive : higherPrincipalUnitGroup.principalUnitSuccQuot F n → Prop}
    (q : higherPrincipalUnitGroup.principalUnitSuccQuot F n)
    (h : ∀ u : higherPrincipalUnitGroup F n,
      motive (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u)) :
    motive q
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotLift

Descend a homomorphism from U^n that kills U^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotLift
    {H : Type*} [Group H] (n : ℕ)
    (f : higherPrincipalUnitGroup F n →* H)
    (h : (higherPrincipalUnitGroup F (n + 1)).subgroupOf
      (higherPrincipalUnitGroup F n) ≤ f.ker) :
    higherPrincipalUnitGroup.principalUnitSuccQuot F n →* H
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotLift_mk

Establishes the identity higherPrincipalUnitGroup.principalUnitSuccQuotLift F n f h (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u) = f u.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotLift_mk
    {H : Type*} [Group H] (n : ℕ)
    (f : higherPrincipalUnitGroup F n →* H)
    (h : (higherPrincipalUnitGroup F (n + 1)).subgroupOf
      (higherPrincipalUnitGroup F n) ≤ f.ker)
    (u : higherPrincipalUnitGroup F n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotLift F n f h
        (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u) = f u
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotFinite

The type in Finite (higherPrincipalUnitGroup.principalUnitSuccQuot F n) is finite.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
instance principalUnitSuccQuotFinite
    [Finite F.residueField] (n : ℕ) :
    Finite (higherPrincipalUnitGroup.principalUnitSuccQuot F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotEquivGradedPiece

The concrete complete-DVF adjacent quotient agrees with the generic graded-piece wrapper through explicit public equivalences.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotEquivGradedPiece (n : ℕ) :
    higherPrincipalUnitGroup.principalUnitSuccQuot F n ≃*
      (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitGradedPiece n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotEquivGradedPiece_mk

Establishes the identity higherPrincipalUnitGroup.principalUnitSuccQuotEquivGradedPiece F n (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u) = (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitGradedPieceMk n u.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotEquivGradedPiece_mk
    (n : ℕ) (u : higherPrincipalUnitGroup F n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotEquivGradedPiece F n
        (higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u) =
      (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitGradedPieceMk
        n u
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotMk_eq_one_iff

Characterizes higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u = 1 by the equivalent condition u ∈ (higherPrincipalUnitGroup F (n + 1)).subgroupOf (higherPrincipalUnitGroup F n).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotMk_eq_one_iff (n : ℕ)
    (u : higherPrincipalUnitGroup F n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u = 1 ↔
      u ∈ (higherPrincipalUnitGroup F (n + 1)).subgroupOf
        (higherPrincipalUnitGroup F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotMk_eq_iff_div_mem

Characterizes higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u = higherPrincipalUnitGroup.principalUnitSuccQuotMk F n v by the equivalent condition u / v ∈ (higherPrincipalUnitGroup F (n + 1)).subgroupOf (higherPrincipalUnitGroup F n).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotMk_eq_iff_div_mem (n : ℕ)
    (u v : higherPrincipalUnitGroup F n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotMk F n u =
        higherPrincipalUnitGroup.principalUnitSuccQuotMk F n v ↔
      u / v ∈ (higherPrincipalUnitGroup F (n + 1)).subgroupOf
        (higherPrincipalUnitGroup F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.mem_succ_subgroupOf_iff

Characterizes u ∈ (higherPrincipalUnitGroup F (n + 1)).subgroupOf (higherPrincipalUnitGroup F n) by the equivalent condition ((u : F.valuationSubringˣ) : F.valuationSubring) - 1 ∈ F.maximalIdeal ^ (n + 1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem mem_succ_subgroupOf_iff (n : ℕ)
    (u : higherPrincipalUnitGroup F n) :
    u ∈ (higherPrincipalUnitGroup F (n + 1)).subgroupOf
        (higherPrincipalUnitGroup F n) ↔
      ((u : F.valuationSubringˣ) : F.valuationSubring) - 1 ∈
        F.maximalIdeal ^ (n + 1)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.isUnit_one_add_of_mem_maximalIdeal_pow

If a ∈ m^n with n ≥ 1, then 1 + a is a unit of the valuation ring.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem isUnit_one_add_of_mem_maximalIdeal_pow {n : ℕ} (hn : 1 ≤ n)
    (a : F.valuationSubring) (ha : a ∈ F.maximalIdeal ^ n) : IsUnit (1 + a)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitOneAddOfMemPow

The unit 1 + a attached to an element a ∈ m^n, for n ≥ 1.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitOneAddOfMemPow {n : ℕ} (hn : 1 ≤ n)
    (a : F.valuationSubring) (ha : a ∈ F.maximalIdeal ^ n) : F.valuationSubringˣ
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitOneAddOfMemPow_val

Establishes the identity ((higherPrincipalUnitGroup.principalUnitOneAddOfMemPow F hn a ha : F.valuationSubringˣ) : F.valuationSubring) = 1 + a.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitOneAddOfMemPow_val {n : ℕ} (hn : 1 ≤ n)
    (a : F.valuationSubring) (ha : a ∈ F.maximalIdeal ^ n) :
    ((higherPrincipalUnitGroup.principalUnitOneAddOfMemPow F hn a ha :
        F.valuationSubringˣ) : F.valuationSubring) =
      1 + a
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitOneAddOfMemPowSubgroup

The unit 1 + a, viewed as an element of U^n.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitOneAddOfMemPowSubgroup {n : ℕ} (hn : 1 ≤ n)
    (a : F.valuationSubring) (ha : a ∈ F.maximalIdeal ^ n) :
    higherPrincipalUnitGroup F n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitOneAddOfMemPowSubgroup_val

Establishes the identity ((higherPrincipalUnitGroup.principalUnitOneAddOfMemPowSubgroup F hn a ha : higherPrincipalUnitGroup F n) : F.valuationSubringˣ) = higherPrincipalUnitGroup.principalUnitOneAddOfMemPow F hn a ha.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitOneAddOfMemPowSubgroup_val {n : ℕ} (hn : 1 ≤ n)
    (a : F.valuationSubring) (ha : a ∈ F.maximalIdeal ^ n) :
    ((higherPrincipalUnitGroup.principalUnitOneAddOfMemPowSubgroup F hn a ha :
        higherPrincipalUnitGroup F n) : F.valuationSubringˣ) =
      higherPrincipalUnitGroup.principalUnitOneAddOfMemPow F hn a ha
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow

The concrete map m^n → U^n/U^(n+1) sending a to the class of 1 + a.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotOfIdealPow (n : ℕ) (hn : 1 ≤ n) :
    ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u) →
      higherPrincipalUnitGroup.principalUnitSuccQuot F n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow_apply

The defining evaluation formula for principalUnitSuccQuotOfIdealPow is higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a = higherPrincipalUnitGroup.principalUnitSuccQuotMk F n (higherPrincipalUnitGroup.principalUnitOneAddOfMemPowSubgroup F hn a.1 a.2).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfIdealPow_apply (n : ℕ) (hn : 1 ≤ n)
    (a : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u)) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a =
      higherPrincipalUnitGroup.principalUnitSuccQuotMk F n
        (higherPrincipalUnitGroup.principalUnitOneAddOfMemPowSubgroup F hn a.1 a.2)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow_eq_one_of_mem_succ

Elements of m^(n+1) map to the trivial class in U^n/U^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfIdealPow_eq_one_of_mem_succ
    (n : ℕ) (hn : 1 ≤ n)
    (a : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u))
    (ha : (a : F.valuationSubring) ∈ F.maximalIdeal ^ (n + 1)) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a = 1
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow_eq_of_sub_mem_succ

The map a ↦ [1 + a] is insensitive to changing a modulo m^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfIdealPow_eq_of_sub_mem_succ
    (n : ℕ) (hn : 1 ≤ n)
    (a b : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u))
    (hab : ((a : F.valuationSubring) - (b : F.valuationSubring)) ∈
      F.maximalIdeal ^ (n + 1)) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a =
      higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn b
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow_eq_one_iff

The class [1+a] is trivial exactly when a ∈ m^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfIdealPow_eq_one_iff
    (n : ℕ) (hn : 1 ≤ n)
    (a : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u)) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a = 1 ↔
      (a : F.valuationSubring) ∈ F.maximalIdeal ^ (n + 1)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.maximalIdealPow_mul_mem_succ

Products of two elements of m^n, for n ≥ 1, lie in m^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem maximalIdealPow_mul_mem_succ {n : ℕ} (hn : 1 ≤ n)
    (a b : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u)) :
    ((a : F.valuationSubring) * (b : F.valuationSubring)) ∈
      F.maximalIdeal ^ (n + 1)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow_add

The map a ↦ [1+a] is additive after passing to the successive principal-unit quotient.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfIdealPow_add
    (n : ℕ) (hn : 1 ≤ n)
    (a b : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u)) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn (a + b) =
      higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a *
        higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn b
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot

The descent of a ↦ [1+a] to m^n/m^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotOfMaximalIdealPowSuccQuot
    (n : ℕ) (hn : 1 ≤ n) :
    MaximalIdealPowSuccQuot F.toDVF n →
      higherPrincipalUnitGroup.principalUnitSuccQuot F n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot_mk

Establishes the identity higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn (maximalIdealPowSuccQuotMk F.toDVF n a) = higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuot_mk
    (n : ℕ) (hn : 1 ≤ n)
    (a : ((F.maximalIdeal ^ n : Ideal F.valuationSubring) : Type u)) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn
        (maximalIdealPowSuccQuotMk F.toDVF n a) =
      higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn a
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot_map_zero

principalUnitSuccQuotOfMaximalIdealPowSuccQuot has the zero-value formula higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn 0 = 1.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuot_map_zero
    (n : ℕ) (hn : 1 ≤ n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn 0 = 1
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot_map_add

principalUnitSuccQuotOfMaximalIdealPowSuccQuot satisfies the addition formula higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn (x + y) = higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x * higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn y.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuot_map_add
    (n : ℕ) (hn : 1 ≤ n)
    (x y : MaximalIdealPowSuccQuot F.toDVF n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn (x + y) =
      higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x *
        higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn y
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd

Additive form of the descended map m^n/m^(n+1) → U^n/U^(n+1).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd
    (n : ℕ) (hn : 1 ≤ n) :
    MaximalIdealPowSuccQuot F.toDVF n →+
      Additive (higherPrincipalUnitGroup.principalUnitSuccQuot F n) where
  toFun x := Additive.ofMul
    (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x)
  map_zero' := by
    change Additive.ofMul
        (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn 0) = 0
    simp
  map_add' x y := by
    change Additive.ofMul
        (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn (x + y)) =
      Additive.ofMul
        (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x *
          higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn y)
    rw [higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot_map_add]
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd_apply

The defining evaluation formula for principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd is higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn x = Additive.ofMul (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd_apply
    (n : ℕ) (hn : 1 ≤ n) (x : MaximalIdealPowSuccQuot F.toDVF n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn x =
      Additive.ofMul
        (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot_eq_one_iff

Characterizes higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x = 1 by the equivalent condition x = 0.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuot_eq_one_iff
    (n : ℕ) (hn : 1 ≤ n) (x : MaximalIdealPowSuccQuot F.toDVF n) :
    higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn x = 1 ↔
      x = 0
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot_surjective

The specified map is surjective: Function.Surjective (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuot_surjective
    (n : ℕ) (hn : 1 ≤ n) :
    Function.Surjective
      (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuot F n hn)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd_surjective

The specified map is surjective: Function.Surjective (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd_surjective
    (n : ℕ) (hn : 1 ≤ n) :
    Function.Surjective
      (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd_injective

The specified map is injective: Function.Injective (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn).

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd_injective
    (n : ℕ) (hn : 1 ≤ n) :
    Function.Injective
      (higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot

The additive isomorphism m^n/m^(n+1) ≃ U^n/U^(n+1) induced by a ↦ 1+a.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot
    (n : ℕ) (hn : 1 ≤ n) :
    MaximalIdealPowSuccQuot F.toDVF n ≃+
      Additive (higherPrincipalUnitGroup.principalUnitSuccQuot F n)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot_apply

The defining evaluation formula for maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot is higherPrincipalUnitGroup.maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot F n hn x = higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn x.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot_apply
    (n : ℕ) (hn : 1 ≤ n) (x : MaximalIdealPowSuccQuot F.toDVF n) :
    higherPrincipalUnitGroup.maximalIdealPowSuccQuotAddEquivPrincipalUnitSuccQuot
        F n hn x =
      higherPrincipalUnitGroup.principalUnitSuccQuotOfMaximalIdealPowSuccQuotAdd F n hn x
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotAddEquivResidueOfUniformizer

The unit-quotient coordinate theorem for a complete DVF with a specified uniformizer: U^n/U^(n+1) is additively the residue field.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
def principalUnitSuccQuotAddEquivResidueOfUniformizer
    {pi : F.valuationSubring} (hpi : F.valuation.IsUniformizer (pi : K))
    (n : ℕ) (hn : 1 ≤ n) :
    Additive (higherPrincipalUnitGroup.principalUnitSuccQuot F n) ≃+ F.residueField
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.card_principalUnitSuccQuot_eq_residue_of_uniformizer

Cardinality form of the associated-graded identification U^n/U^(n+1) ≃ k for n ≥ 1.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem card_principalUnitSuccQuot_eq_residue_of_uniformizer
    [Finite F.residueField]
    {pi : F.valuationSubring} (hpi : F.valuation.IsUniformizer (pi : K))
    (n : ℕ) (hn : 1 ≤ n) :
    Nat.card (higherPrincipalUnitGroup.principalUnitSuccQuot F n) =
      Nat.card F.residueField
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.card_principalUnitSubquotient_one_eq_residue_pow_of_uniformizer

Cardinality of the finite principal-unit range U^1/U^n, obtained by iterating the adjacent quotients U^i/U^(i+1) ≃ k.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem card_principalUnitSubquotient_one_eq_residue_pow_of_uniformizer
    [Finite F.residueField]
    {pi : F.valuationSubring} (hpi : F.valuation.IsUniformizer (pi : K))
    {n : ℕ} (hn : 1 ≤ n) :
    Nat.card (higherPrincipalUnitGroup F 1 ⧸
        (higherPrincipalUnitGroup F n).subgroupOf
          (higherPrincipalUnitGroup F 1)) =
      Nat.card F.residueField ^ (n - 1)
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotAddEquivResidueOfUniformizer_symm_residue

Under the inverse of U^n/U^(n+1) ≃ k, the residue of r is represented by the principal unit 1 + r * pi^n.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotAddEquivResidueOfUniformizer_symm_residue
    {pi : F.valuationSubring} (hpi : F.valuation.IsUniformizer (pi : K))
    (n : ℕ) (hn : 1 ≤ n) (r : F.valuationSubring) :
    (higherPrincipalUnitGroup.principalUnitSuccQuotAddEquivResidueOfUniformizer
        F hpi n hn).symm (F.residueMap r) =
      Additive.ofMul
        (higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn
          (maximalIdealPowMulUniformizerPowMap F.toDVF hpi n r))
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.principalUnitSuccQuotAddEquivResidueOfUniformizer_coord

The equivalence U^n/U^(n+1) ≃ k sends the coordinate class [1 + r * pi^n] to the residue of r.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem principalUnitSuccQuotAddEquivResidueOfUniformizer_coord
    {pi : F.valuationSubring} (hpi : F.valuation.IsUniformizer (pi : K))
    (n : ℕ) (hn : 1 ≤ n) (r : F.valuationSubring) :
    higherPrincipalUnitGroup.principalUnitSuccQuotAddEquivResidueOfUniformizer
        F hpi n hn
        (Additive.ofMul
          (higherPrincipalUnitGroup.principalUnitSuccQuotOfIdealPow F n hn
            (maximalIdealPowMulUniformizerPowMap F.toDVF hpi n r))) =
      F.residueMap r
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModPrincipalUnitEquivOfPreserves_mem_principalUnitClassInQuotient_iff

The induced action on O^*/U^n preserves the image of U^m in that quotient. This is the finite-stage principal-unit class compatibility needed before applying prime-to-p quotient invisibility.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem unitsModPrincipalUnitEquivOfPreserves_mem_principalUnitClassInQuotient_iff
    (e : K ≃+* K)
    (hmem :
      ∀ x : K,
        x ∈ F.valuation.valuationSubring ↔
          e x ∈ F.valuation.valuationSubring)
    {m n : ℕ} (hmn : m ≤ n)
    (q : F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n) :
    unitsModPrincipalUnitEquivOfPreserves F e hmem n q ∈
        (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitSubgroupClassInQuotient
          m n ↔
      q ∈
        (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitSubgroupClassInQuotient
          m n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.unitsModPrincipalUnitEquivOfPreserves_div_mem_principalUnitClass_one

If the induced residue-field automorphism is pointwise trivial, then the displacement of the induced action on O^*/U^n lies in the image of U^1/U^n.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem unitsModPrincipalUnitEquivOfPreserves_div_mem_principalUnitClass_one
    (e : K ≃+* K)
    (hmem :
      ∀ x : K,
        x ∈ F.valuation.valuationSubring ↔
          e x ∈ F.valuation.valuationSubring)
    (hres :
      ∀ x : F.residueField,
        valuationSubringResidueFieldEquivOfPreserves F e hmem x = x)
    (n : ℕ)
    (q : F.valuationSubringˣ ⧸ higherPrincipalUnitGroup F n) :
    unitsModPrincipalUnitEquivOfPreserves F e hmem n q / q ∈
      (higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitSubgroupClassInQuotient
        1 n
LocalFieldTheory.DiscreteValuationField.CompleteDVF.higherPrincipalUnitGroup.finite_principalUnitSubgroupClassInQuotient_of_finite_residue

Therefore every adjacent concrete principal-unit class U^i/U^(i+1) is finite when the residue field is finite.

Source context 11 commands

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

namespace LocalFieldTheory
open ValuationTheory
noncomputable section
open scoped BigOperators
universe u v
namespace DiscreteValuationField
namespace CompleteDVF
variable {K : Type u} [Field K]
namespace higherPrincipalUnitGroup
open ValuationTheory.DiscreteValuationField.DVF
variable (F : ValuationTheory.DiscreteValuationField.CompleteDVF.{u, v} K)
theorem finite_principalUnitSubgroupClassInQuotient_of_finite_residue
    [Finite F.residueField] (i : ℕ) :
    Finite
      ((higherPrincipalUnitGroup.toPrincipalUnitFiltration F).principalUnitSubgroupClassInQuotient
        i (i + 1))