A surjection preserving and reflecting all adic congruences is measurable for the adic cylinder σ-algebra.
ProvedTypeDensity.congruence_bijection_measurabletype-density
A surjection preserving and reflecting all adic congruences is measurable for the adic cylinder σ-algebra.
Preamble
import Definitions.Def_TypeDensity_Basic import Definitions.Def_TypeDensity_Measure_AdicCylinders 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 set_option autoImplicit false open TypeDensity open MeasureTheory open scoped BigOperators ENNReal
Formal statement
theorem TypeDensity.congruence_bijection_measurable (O V : Type) [CommRing O] [AddCommGroup V] [Module O V]
(I : Ideal O) [MeasurableSpace V] (hgen : ‹MeasurableSpace V› = adicCylinderSpace I V)
(F : V → V) (honto : Function.Surjective F)
(hcong : ∀ j x y, adicCongr I j (F x) (F y) ↔ adicCongr I j x y) :
Measurable F := by sorrySource
TypeDensity/Measure/AdicCylinders.lean#L550-L565