Module

FixedFieldContinuousNaturality.lean

Nyll.ClassFieldTheory.LocalClassFieldTheory.Finite.LocalReciprocity.FixedFieldContinuousNaturality
32 declarations indexed from sourceView source ↗

Continuous fixed-field naturality diagrams

The algebraic norm--restriction and transfer--inclusion diagrams are upgraded here to diagrams of continuous homomorphisms. Every finite fixed field uses the spectral norm extended from the original local field. Thus no source is made discrete merely to obtain continuity.

Multiplicative forms of the algebraic arrows

The norm kernel

Continuous arrows

Continuous norm--restriction square

Continuous transfer--inclusion square

Declarations

LocalClassFieldTheory.abelianizationQuotientTopologicalSpace

The quotient topology on the algebraic abelianization. Its underlying quotient is opaque to typeclass search, so expose the canonical topology locally while constructing the continuous finite maps.

Source context 6 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G)
LocalClassFieldTheory.abstractFixedFieldNormResidueMonoidHom

The fixed-field norm-residue symbol on the native multiplicative unit group. This is the multiplicative form of abstractFixedFieldNormResidueSymbol.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldNormResidueMonoidHom
    (D : DegreeData (Gal(Ω/k)))
    (v : ValuationData D (galoisAmbientUnitsRep k Ω))
    (hcf : SatisfiesClassFieldAxiom (galoisAmbientUnitsRep k Ω))
    (K L : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    [hnormal : (extensionSubgroup K L hLK).Normal]
    [hfinite : Finite
      (K.toSubgroup ⧸ extensionSubgroup K L hLK)]
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))] :
    (abstractFixedField k Ω K)ˣ →*
      Abelianization
        Gal(abstractRelativeFixedField k Ω hLK /
          abstractFixedField k Ω K)
LocalClassFieldTheory.abstractFixedFieldNormUnitsMonoidHom

The ordinary fixed-field norm on native multiplicative unit groups.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldNormUnitsMonoidHom
    (K K' : ClosedSubgroup (Gal(Ω/k)))
    (hK'K : K'.toSubgroup ≤ K.toSubgroup) :
    (abstractRelativeFixedField k Ω hK'K)ˣ →*
      (abstractFixedField k Ω K)ˣ
LocalClassFieldTheory.abstractFixedFieldUnitsInclusionMonoidHom

Inclusion of native multiplicative fixed-field unit groups.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldUnitsInclusionMonoidHom
    (K K' : ClosedSubgroup (Gal(Ω/k)))
    (hK'K : K'.toSubgroup ≤ K.toSubgroup) :
    (abstractFixedField k Ω K)ˣ →*
      (abstractFixedField k Ω K')ˣ
LocalClassFieldTheory.abstractFixedFieldAbelianizedRestrictionMonoidHom

Restriction on native multiplicative finite abelianizations.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldAbelianizedRestrictionMonoidHom
    (K K' L L' : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    (hL'K' : L'.toSubgroup ≤ K'.toSubgroup)
    (hK'K : K'.toSubgroup ≤ K.toSubgroup)
    (hL'L : L'.toSubgroup ≤ L.toSubgroup)
    [hLnormal : (extensionSubgroup K L hLK).Normal]
    [hL'normal : (extensionSubgroup K' L' hL'K').Normal] :
    Abelianization
        Gal(abstractRelativeFixedField k Ω hL'K' /
          abstractFixedField k Ω K') →*
      Abelianization
        Gal(abstractRelativeFixedField k Ω hLK /
          abstractFixedField k Ω K)
LocalClassFieldTheory.abstractFixedFieldAbelianizedTransferMonoidHom

Transfer on native multiplicative finite abelianizations.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldAbelianizedTransferMonoidHom
    (K K' L : ClosedSubgroup (Gal(Ω/k)))
    (hLK' : L.toSubgroup ≤ K'.toSubgroup)
    (hK'K : K'.toSubgroup ≤ K.toSubgroup)
    [hLnormal :
      (extensionSubgroup K L (hLK'.trans hK'K)).Normal]
    [hLfinite : Finite
      (K.toSubgroup ⧸
        extensionSubgroup K L (hLK'.trans hK'K))] :
    letI : (extensionSubgroup K' L hLK').Normal :=
      transferNormNaturality_intermediateExtension_normal
        K K' L hLK' hK'K
    letI : Finite
        (K'.toSubgroup ⧸ extensionSubgroup K' L hLK') :=
      FiniteGaloisSubextension.finite_extension_over_intermediate
        (hLK'.trans hK'K) hK'K hLK'
    Abelianization
        Gal(abstractRelativeFixedField k Ω
            (hLK'.trans hK'K) /
          abstractFixedField k Ω K) →*
      Abelianization
        Gal(abstractRelativeFixedField k Ω hLK' /
          abstractFixedField k Ω K') :=
  MonoidHom.toAdditive.symm
    (abstractFixedFieldAbelianizedTransfer
      k Ω K K' L hLK' hK'K)
LocalClassFieldTheory.abstractFixedFieldUnitsEquiv_finiteNormSubgroup_preimage

Under the concrete fixed-unit equivalence, the finite abstract norm subgroup pulls back to the ordinary field-norm subgroup.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
theorem abstractFixedFieldUnitsEquiv_finiteNormSubgroup_preimage
    [IsSepClosed Ω]
    (K L : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    [hfinite : Finite
      (K.toSubgroup ⧸ extensionSubgroup K L hLK)]
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))] :
    (finiteNormSubgroup (galoisAmbientUnitsRep k Ω)
        K L hLK).comap
      (abstractFixedFieldUnitsEquivGaloisFixed
        k Ω K).toAddMonoidHom =
      additiveNormSubgroup
        (abstractFixedField k Ω K)
        (abstractRelativeFixedField k Ω hLK)
LocalClassFieldTheory.abstractFixedFieldNormResidueSymbol_ker

The kernel of the additive fixed-field norm-residue symbol is the ordinary norm subgroup, written additively.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
theorem abstractFixedFieldNormResidueSymbol_ker
    (D : DegreeData (Gal(Ω/k)))
    (v : ValuationData D (galoisAmbientUnitsRep k Ω))
    (hcf : SatisfiesClassFieldAxiom (galoisAmbientUnitsRep k Ω))
    [IsSepClosed Ω]
    (K L : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    [hnormal : (extensionSubgroup K L hLK).Normal]
    [hfinite : Finite
      (K.toSubgroup ⧸ extensionSubgroup K L hLK)]
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))] :
    (abstractFixedFieldNormResidueSymbol
      k Ω D v hcf K L hLK).ker =
      additiveNormSubgroup
        (abstractFixedField k Ω K)
        (abstractRelativeFixedField k Ω hLK)
LocalClassFieldTheory.abstractFixedFieldNormResidueMonoidHom_ker

The kernel of the multiplicative fixed-field norm-residue homomorphism is the ordinary norm subgroup.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
theorem abstractFixedFieldNormResidueMonoidHom_ker
    (D : DegreeData (Gal(Ω/k)))
    (v : ValuationData D (galoisAmbientUnitsRep k Ω))
    (hcf : SatisfiesClassFieldAxiom (galoisAmbientUnitsRep k Ω))
    [IsSepClosed Ω]
    (K L : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    [hnormal : (extensionSubgroup K L hLK).Normal]
    [hfinite : Finite
      (K.toSubgroup ⧸ extensionSubgroup K L hLK)]
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))] :
    (abstractFixedFieldNormResidueMonoidHom
      k Ω D v hcf K L hLK).ker =
      localNormSubgroup
        (abstractFixedField k Ω K)
        (abstractRelativeFixedField k Ω hLK)
LocalClassFieldTheory.abstractFixedFieldNormResidueMap

The fixed-field norm-residue symbol, bundled as a genuinely continuous homomorphism for the spectral topology on the source field.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldNormResidueMap
    [ValuativeRel k] [TopologicalSpace k]
    [IsNonarchimedeanLocalField k]
    [IsSepClosed Ω]
    (D : DegreeData (Gal(Ω/k)))
    (v : ValuationData D (galoisAmbientUnitsRep k Ω))
    (hcf : SatisfiesClassFieldAxiom (galoisAmbientUnitsRep k Ω))
    (K L : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    [hnormal : (extensionSubgroup K L hLK).Normal]
    [hfinite : Finite
      (K.toSubgroup ⧸ extensionSubgroup K L hLK)]
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))] :
    letI : FiniteDimensional k (abstractFixedField k Ω K) :=
      abstractFixedField_finiteDimensional k Ω K hKabsolute
    letI : NontriviallyNormedField (abstractFixedField k Ω K) :=
      finiteExtensionSpectralNormedField k (abstractFixedField k Ω K)
    (abstractFixedField k Ω K)ˣ →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k Ω hLK /
          abstractFixedField k Ω K) := by
  let F := abstractFixedField k Ω K
  let E := abstractRelativeFixedField k Ω hLK
  letI : FiniteDimensional k F :=
    abstractFixedField_finiteDimensional k Ω K hKabsolute
  letI : NontriviallyNormedField F :=
    finiteExtensionSpectralNormedField k F
  letI : CompleteSpace F := finiteExtensionSpectralCompleteSpace k F
  letI : ValuativeRel F := finiteExtensionSpectralValuativeRel k F
  letI : IsNonarchimedeanLocalField F :=
    finiteExtensionSpectralIsNonarchimedeanLocalField k F
  letI : FiniteDimensional F E :=
    abstractRelativeFixedField_finiteDimensional
      k Ω K L hLK hKabsolute hfinite
  letI : IsGalois F E :=
    abstractRelativeFixedField_isGalois k Ω K L hLK hnormal
  letI : DiscreteTopology (Abelianization Gal(E / F)) :=
    QuotientGroup.discreteTopology (isOpen_discrete _)
  let f := abstractFixedFieldNormResidueMonoidHom
    k Ω D v hcf K L hLK
  refine { f with continuous_toFun := ?_ }
  apply continuous_of_continuousAt_one f
  rw [ContinuousAt, map_one,
    @nhds_discrete (Abelianization Gal(E / F)) _ _, Filter.tendsto_pure]
  have hopen : IsOpen (f.ker : Set Fˣ) := by
    rw [abstractFixedFieldNormResidueMonoidHom_ker
      k Ω D v hcf K L hLK]
    exact localNormSubgroup_isOpen F E
  exact hopen.mem_nhds (by simp)
LocalClassFieldTheory.abstractFixedFieldNormUnitsMap

The ordinary norm on fixed-field units, continuously bundled for the two spectral topologies extended from the original local field.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldNormUnitsMap
    [ValuativeRel k] [TopologicalSpace k]
    [IsNonarchimedeanLocalField k]
    (K K' : ClosedSubgroup (Gal(Ω/k)))
    (hK'K : K'.toSubgroup ≤ K.toSubgroup)
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))]
    [hK'absolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K'
          (le_baseField K'))]
    [hK'Kfinite : Finite
      (K.toSubgroup ⧸ extensionSubgroup K K' hK'K)] :
    letI : FiniteDimensional k (abstractFixedField k Ω K) :=
      abstractFixedField_finiteDimensional k Ω K hKabsolute
    letI : FiniteDimensional k
        (abstractRelativeFixedField k Ω hK'K) :=
      abstractFixedField_finiteDimensional k Ω K' hK'absolute
    letI : NontriviallyNormedField (abstractFixedField k Ω K) :=
      finiteExtensionSpectralNormedField k (abstractFixedField k Ω K)
    letI : NontriviallyNormedField
        (abstractRelativeFixedField k Ω hK'K) :=
      finiteExtensionSpectralNormedField k
        (abstractRelativeFixedField k Ω hK'K)
    (abstractRelativeFixedField k Ω hK'K)ˣ →ₜ*
      (abstractFixedField k Ω K)ˣ := by
  let F := abstractFixedField k Ω K
  let F' := abstractRelativeFixedField k Ω hK'K
  letI : FiniteDimensional k F :=
    abstractFixedField_finiteDimensional k Ω K hKabsolute
  letI : FiniteDimensional k F' :=
    abstractFixedField_finiteDimensional k Ω K' hK'absolute
  letI : NontriviallyNormedField F :=
    finiteExtensionSpectralNormedField k F
  letI : NontriviallyNormedField F' :=
    finiteExtensionSpectralNormedField k F'
  letI : IsScalarTower k F F' := IsScalarTower.of_algebraMap_eq' rfl
  letI : FiniteDimensional F F' :=
    abstractRelativeFixedField_finiteDimensional
      k Ω K K' hK'K hKabsolute hK'Kfinite
  letI : CompleteSpace F := finiteExtensionSpectralCompleteSpace k F
  letI : NormedAlgebra F F' :=
    finiteExtensionSpectralNormedAlgebra k F F'
  let f := abstractFixedFieldNormUnitsMonoidHom
    k Ω K K' hK'K
  refine { f with continuous_toFun := ?_ }
  change Continuous (LocalFieldTheory.normUnits F F')
  exact normUnits_continuous_of_finiteDimensional F F'
LocalClassFieldTheory.abstractFixedFieldUnitsInclusionMap

Inclusion of fixed-field units, continuously bundled for the two spectral topologies extended from the original local field.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldUnitsInclusionMap
    [ValuativeRel k] [TopologicalSpace k]
    [IsNonarchimedeanLocalField k]
    (K K' : ClosedSubgroup (Gal(Ω/k)))
    (hK'K : K'.toSubgroup ≤ K.toSubgroup)
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))]
    [hK'absolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K'
          (le_baseField K'))] :
    letI : FiniteDimensional k (abstractFixedField k Ω K) :=
      abstractFixedField_finiteDimensional k Ω K hKabsolute
    letI : FiniteDimensional k (abstractFixedField k Ω K') :=
      abstractFixedField_finiteDimensional k Ω K' hK'absolute
    letI : NontriviallyNormedField (abstractFixedField k Ω K) :=
      finiteExtensionSpectralNormedField k (abstractFixedField k Ω K)
    letI : NontriviallyNormedField (abstractFixedField k Ω K') :=
      finiteExtensionSpectralNormedField k (abstractFixedField k Ω K')
    (abstractFixedField k Ω K)ˣ →ₜ*
      (abstractFixedField k Ω K')ˣ := by
  let F := abstractFixedField k Ω K
  let F' := abstractFixedField k Ω K'
  letI : FiniteDimensional k F :=
    abstractFixedField_finiteDimensional k Ω K hKabsolute
  letI : FiniteDimensional k F' :=
    abstractFixedField_finiteDimensional k Ω K' hK'absolute
  letI : NontriviallyNormedField F :=
    finiteExtensionSpectralNormedField k F
  letI : NontriviallyNormedField F' :=
    finiteExtensionSpectralNormedField k F'
  letI : NontriviallyNormedField k :=
    localFieldNontriviallyNormedField k
  letI : IsUltrametricDist k := localFieldIsUltrametricDist k
  letI : CompleteSpace k := inferInstance
  letI : NormedSpace k F := spectralNorm.normedSpace k F
  letI : NormedSpace k F' := spectralNorm.normedSpace k F'
  let f := abstractFixedFieldUnitsInclusionMonoidHom
    k Ω K K' hK'K
  refine { f with continuous_toFun := ?_ }
  exact Continuous.units_map _
    (IntermediateField.inclusion
      (abstractFixedField_le k Ω hK'K)).toLinearMap.continuous_of_finiteDimensional
LocalClassFieldTheory.abstractFixedFieldAbelianizedRestrictionMap

Abelianized restriction, continuously bundled for the finite native Krull quotient topologies.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldAbelianizedRestrictionMap
    (K K' L L' : ClosedSubgroup (Gal(Ω/k)))
    (hLK : L.toSubgroup ≤ K.toSubgroup)
    (hL'K' : L'.toSubgroup ≤ K'.toSubgroup)
    (hK'K : K'.toSubgroup ≤ K.toSubgroup)
    (hL'L : L'.toSubgroup ≤ L.toSubgroup)
    [hLnormal : (extensionSubgroup K L hLK).Normal]
    [hL'normal : (extensionSubgroup K' L' hL'K').Normal]
    [hL'K'finite : Finite
      (K'.toSubgroup ⧸ extensionSubgroup K' L' hL'K')]
    [hK'absolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K'
          (le_baseField K'))] :
    Abelianization
        Gal(abstractRelativeFixedField k Ω hL'K' /
          abstractFixedField k Ω K') →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k Ω hLK /
          abstractFixedField k Ω K)
LocalClassFieldTheory.abstractFixedFieldAbelianizedTransferMap

Abelianized transfer, continuously bundled for the finite native Krull quotient topologies.

Source context 7 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
def abstractFixedFieldAbelianizedTransferMap
    (K K' L : ClosedSubgroup (Gal(Ω/k)))
    (hLK' : L.toSubgroup ≤ K'.toSubgroup)
    (hK'K : K'.toSubgroup ≤ K.toSubgroup)
    [hLnormal :
      (extensionSubgroup K L (hLK'.trans hK'K)).Normal]
    [hLfinite : Finite
      (K.toSubgroup ⧸
        extensionSubgroup K L (hLK'.trans hK'K))]
    [hKabsolute : Finite
      ((baseField (Gal(Ω/k))).toSubgroup ⧸
        extensionSubgroup (baseField (Gal(Ω/k))) K
          (le_baseField K))] :
    letI : (extensionSubgroup K' L hLK').Normal :=
      transferNormNaturality_intermediateExtension_normal
        K K' L hLK' hK'K
    letI : Finite
        (K'.toSubgroup ⧸ extensionSubgroup K' L hLK') :=
      FiniteGaloisSubextension.finite_extension_over_intermediate
        (hLK'.trans hK'K) hK'K hLK'
    Abelianization
        Gal(abstractRelativeFixedField k Ω
            (hLK'.trans hK'K) /
          abstractFixedField k Ω K) →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k Ω hLK' /
          abstractFixedField k Ω K') := by
  letI : (extensionSubgroup K' L hLK').Normal :=
    transferNormNaturality_intermediateExtension_normal
      K K' L hLK' hK'K
  letI : Finite
      (K'.toSubgroup ⧸ extensionSubgroup K' L hLK') :=
    FiniteGaloisSubextension.finite_extension_over_intermediate
      (hLK'.trans hK'K) hK'K hLK'
  let F := abstractFixedField k Ω K
  let E := abstractRelativeFixedField k Ω
    (hLK'.trans hK'K)
  letI : FiniteDimensional F E :=
    abstractRelativeFixedField_finiteDimensional
      k Ω K L (hLK'.trans hK'K) hKabsolute hLfinite
  letI : IsGalois F E :=
    abstractRelativeFixedField_isGalois
      k Ω K L (hLK'.trans hK'K) hLnormal
  letI : DiscreteTopology (Abelianization Gal(E / F)) :=
    QuotientGroup.discreteTopology (isOpen_discrete _)
  let f := abstractFixedFieldAbelianizedTransferMonoidHom
    k Ω K K' L hLK' hK'K
  exact { f with continuous_toFun := continuous_of_discreteTopology }
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.lowerNormResidueMap

The lower horizontal norm-residue arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def lowerNormResidueMap
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.lowerBase T.lowerAbsoluteFinite
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.lowerBase)
    (abstractFixedField k (SeparableClosure k) T.lowerBase)ˣ →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k (SeparableClosure k)
            T.lowerTop_le_lowerBase /
          abstractFixedField k (SeparableClosure k) T.lowerBase) := by
  letI := T.lowerNormal
  letI := T.lowerFinite
  letI := T.lowerAbsoluteFinite
  exact abstractFixedFieldNormResidueMap
    k (SeparableClosure k)
    (localResidueDatum k) (localHenselianValuation k)
    (separableClosureUnits_isClassFormation k)
    T.lowerBase T.lowerTop T.lowerTop_le_lowerBase
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.lowerNormResidueMap_toMonoidHom

Forgetting continuity recovers the lower algebraic norm-residue map.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem lowerNormResidueMap_toMonoidHom
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.lowerBase T.lowerAbsoluteFinite
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.lowerBase)
    (lowerNormResidueMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (lowerNormResidueSymbol T) := rfl
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.upperNormResidueMap

The upper horizontal norm-residue arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def upperNormResidueMap
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.upperBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.upperBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.upperBase)
    (abstractFixedField k (SeparableClosure k) T.upperBase)ˣ →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k (SeparableClosure k)
            T.upperTop_le_upperBase /
          abstractFixedField k (SeparableClosure k) T.upperBase) := by
  letI := T.upperNormal
  letI := T.upperFinite
  letI := upperAbsoluteFinite T
  exact abstractFixedFieldNormResidueMap
    k (SeparableClosure k)
    (localResidueDatum k) (localHenselianValuation k)
    (separableClosureUnits_isClassFormation k)
    T.upperBase T.upperTop T.upperTop_le_upperBase
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.upperNormResidueMap_toMonoidHom

Forgetting continuity recovers the upper algebraic norm-residue map.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem upperNormResidueMap_toMonoidHom
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.upperBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.upperBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.upperBase)
    (upperNormResidueMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (upperNormResidueSymbol T) := rfl
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.normUnitsMap

The vertical ordinary norm arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def normUnitsMap
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.lowerBase T.lowerAbsoluteFinite
    letI : FiniteDimensional k
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.lowerBase)
    letI : NontriviallyNormedField
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase)
    (abstractRelativeFixedField k (SeparableClosure k)
        T.upperBase_le_lowerBase)ˣ →ₜ*
      (abstractFixedField k (SeparableClosure k) T.lowerBase)ˣ := by
  letI := T.lowerAbsoluteFinite
  letI := upperAbsoluteFinite T
  letI := T.baseFinite
  exact abstractFixedFieldNormUnitsMap
    k (SeparableClosure k)
    T.lowerBase T.upperBase T.upperBase_le_lowerBase
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.normUnitsMap_toMonoidHom

Forgetting continuity recovers the algebraic norm on units.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem normUnitsMap_toMonoidHom
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.lowerBase T.lowerAbsoluteFinite
    letI : FiniteDimensional k
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.lowerBase)
    letI : NontriviallyNormedField
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase)
    (normUnitsMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (normUnits T) := rfl
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.abelianizedRestrictionMap

The vertical abelianized restriction arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def abelianizedRestrictionMap
    (T : LocalFixedFieldNormRestrictionSquare k)
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.abelianizedRestrictionMap_toMonoidHom

Forgetting continuity recovers algebraic abelianized restriction.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem abelianizedRestrictionMap_toMonoidHom
    (T : LocalFixedFieldNormRestrictionSquare k) :
    (abelianizedRestrictionMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (abelianizedRestriction T)
LocalClassFieldTheory.LocalFixedFieldNormRestrictionSquare.norm_restriction_commutes_continuous

Norm--restriction naturality as a commuting square of continuous homomorphisms.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldNormRestrictionSquare
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem norm_restriction_commutes_continuous
    (T : LocalFixedFieldNormRestrictionSquare k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.lowerBase T.lowerAbsoluteFinite
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.upperBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
    letI : FiniteDimensional k
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.lowerBase)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.upperBase) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.upperBase)
    letI : NontriviallyNormedField
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase) :=
      finiteExtensionSpectralNormedField k
        (abstractRelativeFixedField k (SeparableClosure k)
          T.upperBase_le_lowerBase)
    (abelianizedRestrictionMap T).comp (upperNormResidueMap T) =
      (lowerNormResidueMap T).comp (normUnitsMap T) := by
  let : FiniteDimensional k
      (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
    abstractFixedField_finiteDimensional
      k (SeparableClosure k) T.lowerBase T.lowerAbsoluteFinite
  let : FiniteDimensional k
      (abstractFixedField k (SeparableClosure k) T.upperBase) :=
    abstractFixedField_finiteDimensional
      k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
  let : FiniteDimensional k
      (abstractRelativeFixedField k (SeparableClosure k)
        T.upperBase_le_lowerBase) :=
    abstractFixedField_finiteDimensional
      k (SeparableClosure k) T.upperBase (upperAbsoluteFinite T)
  let : NontriviallyNormedField
      (abstractFixedField k (SeparableClosure k) T.lowerBase) :=
    finiteExtensionSpectralNormedField k
      (abstractFixedField k (SeparableClosure k) T.lowerBase)
  let : NontriviallyNormedField
      (abstractFixedField k (SeparableClosure k) T.upperBase) :=
    finiteExtensionSpectralNormedField k
      (abstractFixedField k (SeparableClosure k) T.upperBase)
  let : NontriviallyNormedField
      (abstractRelativeFixedField k (SeparableClosure k)
        T.upperBase_le_lowerBase) :=
    finiteExtensionSpectralNormedField k
      (abstractRelativeFixedField k (SeparableClosure k)
        T.upperBase_le_lowerBase)
  apply ContinuousMonoidHom.ext
  intro x
  change Additive.toMul
      (abelianizedRestriction T
        (upperNormResidueSymbol T (Additive.ofMul x))) =
    Additive.toMul
      (lowerNormResidueSymbol T
        (normUnits T (Additive.ofMul x)))
  exact congrArg Additive.toMul
    (DFunLike.congr_fun (norm_restriction_commutes T)
      (Additive.ofMul x))
LocalClassFieldTheory.LocalFixedFieldTransferTower.baseNormResidueMap

The total horizontal norm-residue arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def baseNormResidueMap
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.base) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.base T.baseAbsoluteFinite
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.base) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.base)
    (abstractFixedField k (SeparableClosure k) T.base)ˣ →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k (SeparableClosure k)
            (T.top_le_intermediate.trans T.intermediate_le_base) /
          abstractFixedField k (SeparableClosure k) T.base) := by
  letI := T.totalNormal
  letI := T.totalFinite
  letI := T.baseAbsoluteFinite
  exact abstractFixedFieldNormResidueMap
    k (SeparableClosure k)
    (localResidueDatum k) (localHenselianValuation k)
    (separableClosureUnits_isClassFormation k)
    T.base T.top
    (T.top_le_intermediate.trans T.intermediate_le_base)
LocalClassFieldTheory.LocalFixedFieldTransferTower.baseNormResidueMap_toMonoidHom

Forgetting continuity recovers the total algebraic norm-residue map.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem baseNormResidueMap_toMonoidHom
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.base) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.base T.baseAbsoluteFinite
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.base) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.base)
    (baseNormResidueMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (baseNormResidueSymbol T) := rfl
LocalClassFieldTheory.LocalFixedFieldTransferTower.intermediateNormResidueMap

The intermediate horizontal norm-residue arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def intermediateNormResidueMap
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.intermediate
          (intermediateAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.intermediate)
    (abstractFixedField k (SeparableClosure k) T.intermediate)ˣ →ₜ*
      Abelianization
        Gal(abstractRelativeFixedField k (SeparableClosure k)
            T.top_le_intermediate /
          abstractFixedField k (SeparableClosure k) T.intermediate) := by
  letI := intermediateNormal T
  letI := intermediateFinite T
  letI := intermediateAbsoluteFinite T
  exact abstractFixedFieldNormResidueMap
    k (SeparableClosure k)
    (localResidueDatum k) (localHenselianValuation k)
    (separableClosureUnits_isClassFormation k)
    T.intermediate T.top T.top_le_intermediate
LocalClassFieldTheory.LocalFixedFieldTransferTower.intermediateNormResidueMap_toMonoidHom

Forgetting continuity recovers the intermediate norm-residue map.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem intermediateNormResidueMap_toMonoidHom
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.intermediate
          (intermediateAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.intermediate)
    (intermediateNormResidueMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (intermediateNormResidueSymbol T) := rfl
LocalClassFieldTheory.LocalFixedFieldTransferTower.unitsInclusionMap

The vertical inclusion of fixed-field units as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def unitsInclusionMap
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.base) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.base T.baseAbsoluteFinite
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.intermediate
          (intermediateAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.base) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.base)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.intermediate)
    (abstractFixedField k (SeparableClosure k) T.base)ˣ →ₜ*
      (abstractFixedField k (SeparableClosure k) T.intermediate)ˣ := by
  letI := T.baseAbsoluteFinite
  letI := intermediateAbsoluteFinite T
  exact abstractFixedFieldUnitsInclusionMap
    k (SeparableClosure k)
    T.base T.intermediate T.intermediate_le_base
LocalClassFieldTheory.LocalFixedFieldTransferTower.unitsInclusionMap_toMonoidHom

Forgetting continuity recovers algebraic inclusion of fixed-field units.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem unitsInclusionMap_toMonoidHom
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.base) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.base T.baseAbsoluteFinite
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.intermediate
          (intermediateAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.base) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.base)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.intermediate)
    (unitsInclusionMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (unitsInclusion T) := rfl
LocalClassFieldTheory.LocalFixedFieldTransferTower.abelianizedTransferMap

The vertical abelianized transfer arrow as a continuous homomorphism.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
def abelianizedTransferMap
    (T : LocalFixedFieldTransferTower k)
LocalClassFieldTheory.LocalFixedFieldTransferTower.abelianizedTransferMap_toMonoidHom

Forgetting continuity recovers algebraic abelianized transfer.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem abelianizedTransferMap_toMonoidHom
    (T : LocalFixedFieldTransferTower k) :
    (abelianizedTransferMap T).toMonoidHom =
      MonoidHom.toAdditive.symm (abelianizedTransfer T)
LocalClassFieldTheory.LocalFixedFieldTransferTower.transfer_inclusion_commutes_continuous

Transfer--inclusion naturality as a commuting square of continuous homomorphisms.

Source context 9 commands

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

noncomputable section
namespace LocalClassFieldTheory
open scoped NNReal ValuativeRel
open LocalFieldTheory RamificationTheory CyclicCohomology KummerTheory
open ClassFormation LocalClassFieldTheory
variable (k Ω : Type) [Field k] [Field Ω] [Algebra k Ω] [IsGalois k Ω]
/-- The quotient topology on the algebraic abelianization.  Its underlying
quotient is opaque to typeclass search, so expose the canonical topology
locally while constructing the continuous finite maps. -/
private local instance abelianizationQuotientTopologicalSpace
    (G : Type*) [Group G] [TopologicalSpace G] :
    TopologicalSpace (Abelianization G) := by
  change TopologicalSpace (G ⧸ commutator G)
  exact QuotientGroup.instTopologicalSpace (commutator G)
namespace LocalFixedFieldTransferTower
variable {k : Type} [Field k] [ValuativeRel k] [TopologicalSpace k]
  [IsNonarchimedeanLocalField k]
theorem transfer_inclusion_commutes_continuous
    (T : LocalFixedFieldTransferTower k) :
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.base) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.base T.baseAbsoluteFinite
    letI : FiniteDimensional k
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      abstractFixedField_finiteDimensional
        k (SeparableClosure k) T.intermediate
          (intermediateAbsoluteFinite T)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.base) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.base)
    letI : NontriviallyNormedField
        (abstractFixedField k (SeparableClosure k) T.intermediate) :=
      finiteExtensionSpectralNormedField k
        (abstractFixedField k (SeparableClosure k) T.intermediate)
    (abelianizedTransferMap T).comp (baseNormResidueMap T) =
      (intermediateNormResidueMap T).comp (unitsInclusionMap T) := by
  let : FiniteDimensional k
      (abstractFixedField k (SeparableClosure k) T.base) :=
    abstractFixedField_finiteDimensional
      k (SeparableClosure k) T.base T.baseAbsoluteFinite
  let : FiniteDimensional k
      (abstractFixedField k (SeparableClosure k) T.intermediate) :=
    abstractFixedField_finiteDimensional
      k (SeparableClosure k) T.intermediate
        (intermediateAbsoluteFinite T)
  let : NontriviallyNormedField
      (abstractFixedField k (SeparableClosure k) T.base) :=
    finiteExtensionSpectralNormedField k
      (abstractFixedField k (SeparableClosure k) T.base)
  let : NontriviallyNormedField
      (abstractFixedField k (SeparableClosure k) T.intermediate) :=
    finiteExtensionSpectralNormedField k
      (abstractFixedField k (SeparableClosure k) T.intermediate)
  apply ContinuousMonoidHom.ext
  intro x
  change Additive.toMul
      (abelianizedTransfer T
        (baseNormResidueSymbol T (Additive.ofMul x))) =
    Additive.toMul
      (intermediateNormResidueSymbol T
        (unitsInclusion T (Additive.ofMul x)))
  exact congrArg Additive.toMul
    (DFunLike.congr_fun (transfer_inclusion_commutes T)
      (Additive.ofMul x))