Module

ActualNormalizationResidueExactness.lean

Nyll.EtaleFundamentalGroups.Inertia.ActualNormalizationResidueExactness
2 declarations indexed from sourceView source ↗

Exactness at the original decomposition group

The actual inclusion is injective. Mapping into the original Galois group identifies its range with the original inertia subgroup; the already proved residue-kernel image then gives literal equality of subgroups of D.

Declarations

EtaleFundamentalGroups.Inertia.actualNormalizationInertiaToDecomposition_injective

Original inertia includes injectively into original decomposition.

Source context 5 commands

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

namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
attribute [local instance] normalizationCommAlgGaloisAction
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing 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)
theorem actualNormalizationInertiaToDecomposition_injective :
    Function.Injective (actualNormalizationInertiaToDecomposition A K L Q).toFun
EtaleFundamentalGroups.Inertia.actualNormalizationResidueMorphism_ker

The first sequence is exact at the SAME original decomposition group.

Source context 5 commands

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

namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
attribute [local instance] normalizationCommAlgGaloisAction
variable (A : Type u) (K : Type v) (L : Type w)
  [CommRing 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)
theorem actualNormalizationResidueMorphism_ker :
    (normalizationResidueMorphism A K L Q).hom'.ker =
      (actualNormalizationInertiaToDecomposition A K L Q).range