For `g` irreducible and separable over `Frac O`, the integral closure of `O` in `K[X]/(g)` is a finite `O`-module.
ProvedTypeDensity.closure_finite_of_separabletype-density
For g irreducible and separable over Frac O, the integral closure of O in K[X]/(g) is a finite O-module.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Formula_LawAlgebra import Definitions.Def_TypeDensity_Algebra_AlgebraType import Mathlib.FieldTheory.RatFunc.Basic import Mathlib.MeasureTheory.Measure.Haar.Unique import Mathlib.NumberTheory.ArithmeticFunction.Moebius import Mathlib.NumberTheory.Padics.PadicIntegers import Mathlib.RingTheory.IntegralClosure.IntegralRestrict import Mathlib.RingTheory.MvPowerSeries.Basic import Mathlib.RingTheory.RamificationInertia.Basic import Mathlib.Topology.Algebra.Nonarchimedean.AdicTopology import Mathlib.FieldTheory.Finite.GaloisField import Mathlib.RingTheory.AdicCompletion.Algebra import Mathlib.RingTheory.RegularLocalRing.Defs import Mathlib.RingTheory.Henselian set_option autoImplicit false open TypeDensity open scoped TensorProduct open Polynomial IsLocalRing
Formal statement
theorem TypeDensity.closure_finite_of_separable (O : Type) [CommRing O] [IsDomain O]
[IsDiscreteValuationRing O] (g : (FractionRing O)[X]) (hirr : Irreducible g)
(hs : g.Separable) : Module.Finite O (integralClosure O (AdjoinRoot g)) := by sorrySource
TypeDensity/Algebra/AlgebraType.lean#L333-L342