Module

ActualFiniteResidueActionSquare.lean

Nyll.EtaleFundamentalGroups.Inertia.ActualFiniteResidueActionSquare
1 declaration indexed from sourceView source ↗

The actual finite residue-action square

The canonical residue embedding intertwines the actual finite stabilizer action and the original decomposition residue action. Every coefficient formula and the underlying inclusion square are independently proved.

Declarations

EtaleFundamentalGroups.Inertia.actualFiniteNormalizationResidueMap_action
Source context 3 commands

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

namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
theorem actualFiniteNormalizationResidueMap_action
    (A : Type u) (K : Type v) (L : Type w)
    [CommRing A] [IsDomain A] [IsDiscreteValuationRing A]
    [Field K] [Field L] [Algebra A K] [IsFractionRing A K]
    [Algebra K L] [Algebra A L] [IsScalarTower A K L] [IsGalois K L]
    (Q : Ideal (normalizationCommAlgCat A L).carrier) [Q.IsMaximal]
    (E : FiniteGaloisIntermediateField K L)
    (d : (normalizationDecompositionGroup A K L Q).carrier) :
    let : (finiteAbsoluteNormalizationPrime A K L Q E).IsPrime :=
      finiteAbsoluteNormalizationPrime_isPrime A K L Q E
    ∀ x : (finiteAbsoluteNormalizationPrime A K L Q E).ResidueField,
      (actualFiniteNormalizationResidueMap A K L Q E).toFun
          ((actualFiniteDecompositionResidueFieldMap A K L Q E d).toFun x) =
        (actualNormalizationResidueFieldMap A K L Q d).toFun
          ((actualFiniteNormalizationResidueMap A K L Q E).toFun x) := by
  intro finitePrime x
  have : (finiteAbsoluteNormalizationPrime A K L Q E).IsMaximal :=
    actualFiniteNormalizationPrime_isMaximal A K L Q E
  exact residueMap_coefficient_naturality
    (finiteAbsoluteNormalizationPrime A K L Q E) Q
    (finiteAbsoluteNormalizationRingMap A K L E) rfl
    (actualFiniteNormalizationRestrictionRingHom A K L E d.val)
    (normalizationGaloisRingHom A K L d.val)
    (actualFiniteDecompositionResidueFieldMap A K L Q E d)
    (actualNormalizationResidueFieldMap A K L Q d)
    (actualFiniteDecompositionResidueFieldMap_coefficient A K L Q E d)
    (actualNormalizationResidueFieldMap_coefficient A K L Q d)
    (actualFiniteNormalizationRestrictionRingHom_inclusion A K L E d.val) x