`(C/I) / e(C/I) ≃ C/(I + (e))` as `O`-modules, compatibly with the quotient maps.
ProvedTypeDensity.quotient_mul_range_equivtype-density
(C/I) / e(C/I) ≃ C/(I + (e)) as O-modules, compatibly with the quotient maps.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Measure_AdicCylinders import Definitions.Def_TypeDensity_Measure_HenselProducts 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.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.RegularLocalRing.Defs import Mathlib.RingTheory.SimpleRing.Principal set_option autoImplicit false open TypeDensity open MeasureTheory open scoped BigOperators ENNReal
Formal statement
theorem TypeDensity.quotient_mul_range_equiv (O C : Type) [CommRing O] [CommRing C] [Algebra O C] (I : Ideal C)
(e : C) :
∃ φ : ((C ⧸ I) ⧸ LinearMap.range (LinearMap.mulLeft O (Ideal.Quotient.mk I e))) ≃ₗ[O]
(C ⧸ (I ⊔ Ideal.span {e})),
∀ x : C, φ (Submodule.Quotient.mk (Ideal.Quotient.mk I x)) =
Ideal.Quotient.mk (I ⊔ Ideal.span {e}) x := by sorrySource
TypeDensity/Measure/HenselProducts.lean#L1103-L1142