Module

HerbrandFunctionAtLowerIndexStrictMono.lean

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

Strict growth of the integral-index Herbrand function

For a finite extension, each lower ramification group is finite and nonempty. Thus every increment of the rational Herbrand function is strictly positive. This does not assert integrality of its values.

Declarations

ClassFieldTheory.herbrandFunctionAtLowerIndex_strictMono

The rational Herbrand function at nonnegative integral lower indices is strictly increasing for a finite field extension.

Source context 2 commands

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

namespace ClassFieldTheory
universe u v
theorem herbrandFunctionAtLowerIndex_strictMono
    (K : Type u) {L : Type v} [Field K] [Field L] [Algebra K L]
    [FiniteDimensional K L] (A : ValuationSubring L) :
    StrictMono (herbrandFunctionAtLowerIndex K A)