English
Under suitable hypotheses, condExp of a trajectory functional can be represented via a conditional trajectory decomposition with respect to a filtration and a product kernel.
Русский
При подходящих гипотезах условное ожидание функционала траектории представимо через разложение траектории относительно фильтрации и произведения ядер.
LaTeX
$$$\\text{condExp}_{\\mathcal{F}}(f) = \\text{comp}(\\text{traj}, \\text{partialTraj})$$$
Lean4
theorem measurableSet_kernel_integrable ⦃f : α → β → E⦄ (hf : StronglyMeasurable (uncurry f)) :
MeasurableSet {x | Integrable (f x) (κ x)} :=
by
simp_rw [Integrable, hf.of_uncurry_left.aestronglyMeasurable, true_and]
exact measurableSet_lt (Measurable.lintegral_kernel_prod_right hf.enorm) measurable_const