Finite stopping-time Lévy strong Markov with no stopped-reward measurability assumption
ProvedAvramDividend.Classical.levy_finiteStopping_scalar_markov_no_meas_premiseavram-classicalfuture-pathmeasurabilitystopping-timestrong-markov
The expected bounded continuous and product-measurable nonnegative reward of the Lévy future increment path, restricted to a stopped-history event, factors exactly into the event probability and the original-path reward expectation at any finite stopping time. All stopped-reward measurability is derived internally using bounded truncations and adapted grids.
Preamble
import Mathlib.Probability.Process.Stopping import Mathlib.Order.WithBot import Definitions.Def_AvramDividend_Classical_SpectrallyNegativeLevy import Theorems.Thm_AvramDividend_Classical_stoppedHistory_event_min_const import Theorems.Thm_AvramDividend_Classical_levy_boundedStopping_stoppedFutureReward_measurable import Theorems.Thm_AvramDividend_Classical_levy_finiteStopping_boundedReward_scalar_markov open MeasureTheory ProbabilityTheory Filter Set open scoped NNReal ENNReal open AvramDividend.Classical
Formal statement
theorem AvramDividend.Classical.levy_finiteStopping_scalar_markov_no_meas_premise
{Ω : Type*} [mΩ : MeasurableSpace Ω] {P : Measure Ω}
{𝓕 : Filtration ℝ≥0 mΩ}
(X : SpectrallyNegativeLevy P 𝓕)
(τ : Ω → ℝ≥0)
(hstop : IsStoppingTime 𝓕 (fun ω => (τ ω : WithTop ℝ≥0)))
(A : Set Ω)
(hA : ∀ s : ℝ≥0,
MeasurableSet[𝓕 s] (A ∩ {ω : Ω | τ ω ≤ s}))
(g : (ℝ≥0 → ℝ) → ℝ≥0∞)
(hg : Continuous g) (hgm : Measurable g)
(C : ℝ≥0∞) (hbound : ∀ y, g y ≤ C)
(hfin : (∫⁻ _ : Ω, C ∂P) ≠ ∞) :
(∫⁻ ω, Set.indicator A
(fun ω' : Ω => g (fun t : ℝ≥0 =>
X.X (τ ω' + t) ω' - X.X (τ ω') ω')) ω ∂P) =
P A * (∫⁻ y, g y ∂(Measure.map
(fun ω : Ω => fun t : ℝ≥0 => X.X t ω) P)) := by
sorrySource
Uses Proved bounded stopped-future reward measurability and existing canonical finite stopping scalar theorem. Strengthens the strong Markov input to Open stopped-path law 61930a38-11f1-449e-bbb6-67d59c6d5ca8, needed for barrier child 79978d61-9d1f-4b20-b8a5-114797a8e380.