The image of a measurable set of coordinates under a division chart is measurable for the chart σ-algebra on ideals.
ProvedTypeDensity.chart_image_measurable_chart_sigmatype-density
The image of a measurable set of coordinates under a division chart is measurable for the chart σ-algebra on ideals.
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 scoped ENNReal
Formal statement
theorem TypeDensity.chart_image_measurable_chart_sigma (O R : Type) [CommRing O] [CommRing R] [Algebra O R]
[MeasurableSpace O] (pi : O) (n : ℕ) (f : R) (b : Fin n → R)
(hchart : IsDivisionChart O R pi f b) (S : Set (Fin n → O)) (hS : MeasurableSet S) :
@MeasurableSet (Ideal R) (idealChartSigma O R pi) (coordinateIdeal pi f b '' S) := by sorrySource
TypeDensity/Measure/AdicTransport.lean#L108-L114