English
Finite product of ProgMeasurable functions is ProgMeasurable.
Русский
Конечная произведение прогрессивно измеримых функций также прогрессивно измеримо.
LaTeX
$$$(\\forall c \\in s,\\ \\mathrm{ProgMeasurable}(f, U c)) \\Rightarrow \\mathrm{ProgMeasurable}(f, \\prod_{c \\in s} U c)$$$
Lean4
@[to_additive]
protected theorem finset_prod' {γ} [CommMonoid β] [ContinuousMul β] {U : γ → ι → Ω → β} {s : Finset γ}
(h : ∀ c ∈ s, ProgMeasurable f (U c)) : ProgMeasurable f (∏ c ∈ s, U c) :=
Finset.prod_induction U (ProgMeasurable f) (fun _ _ => ProgMeasurable.mul) (progMeasurable_const _ 1) h