English
If hf : iIndepFun f κ μ and hs : ∀ i, i ∈ S → MeasurableSet[(mβ i).comap (f i)] (s i), then almost surely κ a (⋂ i ∈ S, s i) = ∏ i ∈ S, κ a (s i).
Русский
Если hf : iIndepFun f κ μ и hs : ∀ i, i ∈ S → MeasurableSet[(mβ i).comap (f i)] (s i), то почти наверняка κ a (⋂ i ∈ S, s i) = ∏ i ∈ S, κ a (s i).
LaTeX
$$$ (hf : iIndepFun f κ μ) \\Rightarrow (hs : \\forall i, i \\in S \\Rightarrow MeasurableSet[(mβ i).comap (f i)] (s i)) \Rightarrow \\forall a, κ a (\\bigcap_{i \\in S} s i) = \\prod_{i \\in S} κ a (s i) $$$
Lean4
theorem meas_biInter (hf : iIndepFun f κ μ) (hs : ∀ i, i ∈ S → MeasurableSet[(mβ i).comap (f i)] (s i)) :
∀ᵐ a ∂μ, κ a (⋂ i ∈ S, s i) = ∏ i ∈ S, κ a (s i) :=
hf.iIndep.meas_biInter hs