English
The product over a finite multiset of strongly measurable functions is strongly measurable.
Русский
Произведение функций над конечной мультисетой, каждая из которых сильно измерима, также сильно измеримо.
LaTeX
$$$\forall l:\text{Multiset}(\alpha \to M), \ (\forall f \in l, \text{StronglyMeasurable } f) \Rightarrow \text{StronglyMeasurable } (l.prod)$$
Lean4
@[to_additive (attr := fun_prop, measurability)]
theorem _root_.List.stronglyMeasurable_fun_prod (l : List (α → M)) (hl : ∀ f ∈ l, StronglyMeasurable f) :
StronglyMeasurable fun x => (l.map fun f : α → M => f x).prod := by
simpa only [← Pi.list_prod_apply] using l.stronglyMeasurable_prod hl