Over a complete DVR, the normalized form-product map is a bijection from the product of the factor cells onto the product cell.
ProvedTypeDensity.form_product_bijectiontype-density
Over a complete DVR, the normalized form-product map is a bijection from the product of the factor cells onto the product cell.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Formula_LawAlgebra import Definitions.Def_TypeDensity_Algebra_AlgebraType import Definitions.Def_TypeDensity_Measure_AdicCylinders import Definitions.Def_TypeDensity_Measure_HenselProducts import Definitions.Def_TypeDensity_Unramified_Extension import Definitions.Def_TypeDensity_Measure_PrimitiveLocus import Definitions.Def_TypeDensity_Algebra_FactorInvariant import Theorems.Thm_TypeDensity_form_product_maps_to_and_preserves import Theorems.Thm_TypeDensity_forms_linear_bijective import Theorems.Thm_TypeDensity_formProd_add_smul_dvd import Theorems.Thm_TypeDensity_form_product_congruence_reflects 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 import Mathlib.Topology.Algebra.MvPolynomial import Mathlib.Algebra.Group.Pi.Units import Mathlib.Order.CompletePartialOrder import Mathlib.RingTheory.Polynomial.Resultant.Basic import Mathlib.RingTheory.SimpleRing.Principal import Mathlib.Algebra.GroupWithZero.Submonoid.CancelMulZero import Mathlib.Algebra.Module.StablyFree.Basic import Mathlib.NumberTheory.Padics.RingHoms set_option autoImplicit false open TypeDensity open scoped ENNReal
Formal statement
theorem TypeDensity.form_product_bijection (O : Type) [CommRing O] [IsDomain O] [IsDiscreteValuationRing O]
[IsAdicComplete (IsLocalRing.maximalIdeal O) O] (ι : Type) [Fintype ι] (d : ι → ℕ)
(ν : ∀ i, Fin (d i + 1)) (g : ∀ i, Fin (d i + 1) → IsLocalRing.ResidueField O)
(hgν : ∀ i, g i (ν i) = 1) (hc : FormsCoprime d g) (μ : Fin ((∑ i, d i) + 1))
(hμ : formProd d g μ = 1) :
Set.BijOn (reducedFormProduct O d ν g μ)
(Set.pi Set.univ (fun i => reducedFormCell O (d i) (ν i) (g i)))
(reducedFormCell O (∑ i, d i) μ (formProd d g)) := by sorrySource
TypeDensity/Unramified/PolynomialTypes.lean#L530-L619