Continuous adapted version of a vector Itô process
DefinitionKLSModular_LevyStochCalc_Brownian_VectorItoProcessVersionfunctional-inequalitiesklskls-conjecturekls-modularlog-concavemodule-contextvendored-levystochcalc
Vendored from the LevyStochCalc library at https://github.com/cgarryZA/LevyStochCalc, commit 984dbf0b790031eac05d56fe5a84b65e15e1e932. IsVectorItoVersion X₀ bdrift X records that has continuous sample paths, is strongly measurable with respect to the filtration at every time, and agrees -almost everywhere at every nonnegative time with vectorItoProcess. Its generated projection and recursion declarations are the standard structure operations.
Original module imports
import LevyStochCalc.Brownian.VectorItoProcess
Original declaration excerpt
Shown in the original module context.
structure IsVectorItoVersion (X₀ : Ω → Fin n → ℝ) (bdrift : Fin n → Ω → ℝ → ℝ)
(X : ℝ → Ω → Fin n → ℝ) : Prop where
/-- every path is continuous -/
continuous_path : ∀ ω : Ω, Continuous fun t => X t ω
/-- the process is adapted -/
adapted : ∀ t : ℝ, @MeasureTheory.StronglyMeasurable Ω (Fin n → ℝ) _ (ℱ t) (X t)
/-- at each nonnegative time it agrees almost surely with the vector Itô process -/
ae_eq : ∀ t : ℝ, 0 ≤ t → X t =ᵐ[P] vectorItoProcess W ℱ hcoord H hHm hHp hHs X₀ bdrift t
Module navigation
Direct project imports: LevyStochCalc/Brownian/VectorItoProcess.
Project result: The KLS conjecture.
Original module · LevyStochCalc.Brownian.VectorItoProcessVersion · Frozen source 408915f.
Definition code
import Definitions.Def_KLSModular_LevyStochCalc_Brownian_VectorItoProcess
/-
Copyright (c) 2026 Christian Garry. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Christian Garry
-/
-- Vendored from https://github.com/cgarryZA/LevyStochCalc at commit 984dbf0b790031eac05d56fe5a84b65e15e1e932 (upstream path LevyStochCalc/Brownian/VectorItoProcessVersion.lean; Apache-2.0; provenance in formalization/vendor/vendor-lock.json of the KLS repository)
namespace LevyStochCalc
namespace Brownian
namespace Ito
open MeasureTheory ProbabilityTheory
open scoped NNReal ENNReal
universe u
section VectorVersion
open LevyStochCalc.Brownian.Multidim
variable {Ω : Type u} [MeasurableSpace Ω] {P : Measure Ω} [IsProbabilityMeasure P]
{n d : ℕ} (W : Multidim.MultidimBrownianMotion P d)
(ℱ : Filtration ℝ ‹MeasurableSpace Ω›)
(hcoord : ∀ k : Fin d, IsBrownianFiltration (W.W k) ℱ)
(H : Fin n → Fin d → Ω → ℝ → ℝ)
(hHm : ∀ m k, Measurable (Function.uncurry (H m k)))
(hHp : ∀ m k, Probability.ProgressivelyMeasurable ℱ (H m k))
(hHs : ∀ (m : Fin n) (k : Fin d) (T : ℝ), 0 < T → ∫⁻ ω, ∫⁻ s in Set.Icc (0 : ℝ) T,
(‖H m k ω s‖₊ : ℝ≥0∞) ^ 2 ∂volume ∂P < ⊤)
/-- A continuous adapted `Fin n → ℝ`-valued process agreeing at each nonnegative time with the
vector Itô process `X₀ + ∫ b ds + ∑ₖ ∫ H^{·,k} dWᵏ`. -/
structure IsVectorItoVersion (X₀ : Ω → Fin n → ℝ) (bdrift : Fin n → Ω → ℝ → ℝ)
(X : ℝ → Ω → Fin n → ℝ) : Prop where
/-- every path is continuous -/
continuous_path : ∀ ω : Ω, Continuous fun t => X t ω
/-- the process is adapted -/
adapted : ∀ t : ℝ, @MeasureTheory.StronglyMeasurable Ω (Fin n → ℝ) _ (ℱ t) (X t)
/-- at each nonnegative time it agrees almost surely with the vector Itô process -/
ae_eq : ∀ t : ℝ, 0 ≤ t → X t =ᵐ[P] vectorItoProcess W ℱ hcoord H hHm hHp hHs X₀ bdrift t
variable {W ℱ hcoord H hHm hHp hHs} {X₀ : Ω → Fin n → ℝ} {bdrift : Fin n → Ω → ℝ → ℝ}
{X : ℝ → Ω → Fin n → ℝ}
end VectorVersion
end Ito
end Brownian
end LevyStochCalc
Source
Lean source: https://github.com/cgarryZA/LevyStochCalc/blob/984dbf0b790031eac05d56fe5a84b65e15e1e932/LevyStochCalc/Brownian/VectorItoProcessVersion.lean#L51-L60 (repository human-ai-mathematics/kls-lean, commit 408915f, module `LevyStochCalc.Brownian.VectorItoProcessVersion`, definition bundle `KLSModular_LevyStochCalc_Brownian_VectorItoProcessVersion`; the repository is private at upload time). Vendored from https://github.com/cgarryZA/LevyStochCalc at commit 984dbf0b790031eac05d56fe5a84b65e15e1e932 (Apache-2.0; upstream copyright notice retained in the Lean text).