Module

OriginalFiniteInertiaRestriction.lean

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

Original inertia at finite normalization primes

Proves the coefficient difference condition for restriction of original inertia to the contracted finite normalization prime.

Declarations

EtaleFundamentalGroups.Inertia.originalInertia_finiteNormalization_difference

Every element of the original actual inertia restricts to inertia at the literal finite normalization prime. The finite action and its square are constructed from actual restriction, with no comparison premise.

Source context 3 commands

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

namespace EtaleFundamentalGroups.Inertia
open SchemeTheory
universe u v w
theorem originalInertia_finiteNormalization_difference
    (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 (integralClosure A L)) (E : FiniteGaloisIntermediateField K L)
    (σ : actualNormalizationInertiaGroup A K L Q) :
    ∀ b : finiteAbsoluteNormalizationAlgebra A K L E,
      (finiteAbsoluteNormalizationPrime A K L Q E).carrier
        ((actualFiniteNormalizationRestrictionRingHom A K L E
          (actualNormalizationInertiaElement A K L Q σ)).toFun b - b)