The cokernel of the linear part of the normalization map has the same `O`-length as the cokernel of the quotient map `phi`, and it is injective whenever `phi` is.
ProvedTypeDensity.normalization_linear_part_cokernel_length_eqtype-density
The cokernel of the linear part of the normalization map has the same O-length as the cokernel of the quotient map phi, and it is injective whenever phi is.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Formula_LawAlgebra import Definitions.Def_TypeDensity_Measure_AdicCylinders import Definitions.Def_TypeDensity_Measure_HenselProducts import Definitions.Def_TypeDensity_Surfaces_Lengths import Definitions.Def_TypeDensity_Surfaces_PowerSeries import Definitions.Def_TypeDensity_Formula_FiniteFieldCounts import Definitions.Def_TypeDensity_Formula_StateCombinatorics import Definitions.Def_TypeDensity_Blowup_Directions import Definitions.Def_TypeDensity_Unramified_Extension import Definitions.Def_TypeDensity_Blowup_Charts import Definitions.Def_TypeDensity_Algebra_AlgebraType import Definitions.Def_TypeDensity_Measure_PrimitiveLocus import Definitions.Def_TypeDensity_Algebra_FactorInvariant import Theorems.Thm_TypeDensity_division_equiv_child_coordinates 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.Topology.Algebra.MvPolynomial import Mathlib.Algebra.Group.Pi.Units import Mathlib.Order.CompletePartialOrder import Mathlib.RingTheory.Henselian import Mathlib.RingTheory.Polynomial.Resultant.Basic import Mathlib.RingTheory.SimpleRing.Principal import Mathlib.FieldTheory.Finite.Extension import Mathlib.RingTheory.AdicCompletion.Noetherian import Mathlib.RingTheory.MvPowerSeries.Equiv import Mathlib.RingTheory.PicardGroup import Mathlib.FieldTheory.RatFunc.AsPolynomial import Mathlib.RingTheory.AdicCompletion.Completeness import Mathlib.Algebra.GroupWithZero.Submonoid.CancelMulZero import Mathlib.Algebra.Module.StablyFree.Basic import Mathlib.NumberTheory.Padics.RingHoms import Mathlib.Algebra.Azumaya.Basic import Mathlib.RingTheory.AdicCompletion.RingHom import Mathlib.RingTheory.TotallySplit import Mathlib.RingTheory.AdicCompletion.LocalRing import Mathlib.RingTheory.KrullDimension.NonZeroDivisors set_option autoImplicit false open TypeDensity open scoped BigOperators ENNReal
Formal statement
theorem TypeDensity.normalization_linear_part_cokernel_length_eq (O R C : Type) [CommRing O] [CommRing R]
[CommRing C] [Algebra O R] [Algebra O C] (alpha : R →ₐ[O] C) (f : R) (g e c : C) (d : ℕ)
(_hf : alpha f = e ^ d * g) (n : ℕ) (pi : O) (s : ℕ)
(_hpi : (algebraMap O C pi) ^ s = e ^ d * c)
(b : Fin n → R) (bc : Fin n → C) (E : C ≃ₗ[O] ((Fin n → O) × C))
(hE : ∀ w, E.symm w = divisionMap g bc w)
(phi : (R ⧸ Ideal.span {f}) →ₗ[O] (C ⧸ Ideal.span {g}))
(hphi : ∀ h : R, phi (Ideal.Quotient.mk (Ideal.span {f}) h) =
Ideal.Quotient.mk (Ideal.span {g}) (c * alpha h))
(EB : (R ⧸ Ideal.span {f}) ≃ₗ[O] (Fin n → O))
(hEB : ∀ z : Fin n → O, EB.symm z = Ideal.Quotient.mk (Ideal.span {f}) (coordinateLift b z)) :
Module.length O ((Fin n → O) ⧸ LinearMap.range
(normalizationLinearPart E (pulledVariation alpha c b))) = Module.length O
((C ⧸ Ideal.span {g}) ⧸ LinearMap.range phi) ∧
(Function.Injective phi → Function.Injective
(normalizationLinearPart E (pulledVariation alpha c b))) := by sorrySource
TypeDensity/Blowup/PointTransport.lean#L476-L512