Module

InverseHerbrandFunctionHerbrandFunction.lean

Nyll.ClassFieldTheory.Theorems.HasseArf.InverseHerbrandFunctionHerbrandFunction
1 declaration indexed from sourceView source ↗

The inverse Herbrand function is a left inverse

Declarations

ClassFieldTheory.inverseHerbrandFunction_herbrandFunction

The inverse public Herbrand function recovers every real lower index.

Source context 5 commands

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

noncomputable section
namespace ClassFieldTheory
open LocalFieldTheory
open RamificationTheory.LocalField
open RamificationTheory.HilbertRamification.Higher
theorem inverseHerbrandFunction_herbrandFunction
    (K L : Type) [Field K] [Field L] [Algebra K L]
    [FiniteDimensional K L] [IsAbelianGalois K L]
    [ValuativeRel K] [TopologicalSpace K]
    [IsNonarchimedeanLocalField K]
    [ValuativeRel L] [TopologicalSpace L]
    [IsNonarchimedeanLocalField L]
    [Valuation.HasExtension (ValuativeRel.valuation K) (ValuativeRel.valuation L)]
    (s : ℝ) :
    inverseHerbrandFunction K L
      (ClassFieldTheory.herbrandFunction K
        (ValuativeRel.valuation L).valuationSubring s) = s