English
If f is AEStronglyMeasurable, then the ω-average of ∫ f d condExpKernel μ m ω is AEStronglyMeasurable (nontriviality assumed).
Русский
Если f — AEStronglyMeasurable, то интеграл по ядру condExpKernel также AEStronglyMeasurable почти наверху по ω.
LaTeX
$$$\\text{AEStronglyMeasurable}(f)\\Rightarrow \\text{AEStronglyMeasurable}_{μ}(\\omega\\mapsto \\int y\\; f(y)\\; d condExpKernel(\\mu,m)(\\omega))$$$
Lean4
theorem aestronglyMeasurable_integral_condExpKernel [NormedSpace ℝ F] (hf : AEStronglyMeasurable f μ) :
AEStronglyMeasurable[m] (fun ω => ∫ y, f y ∂condExpKernel μ m ω) μ :=
by
nontriviality Ω
rw [condExpKernel_eq]
have h :=
aestronglyMeasurable_integral_condDistrib (aemeasurable_id'' μ (inf_le_right : m ⊓ mΩ ≤ mΩ)) aemeasurable_id
(hf.comp_snd_map_prod_id (inf_le_right : m ⊓ mΩ ≤ mΩ))
rw [MeasurableSpace.comap_id] at h
exact h.mono inf_le_left