∀ {ι : Type u_2} {α : ι → Type u_1} [inst : (i : ι) → MeasurableSpace (α i)] {t : Set ((i : ι) → α i)}
  (ht : t ∈ MeasureTheory.measurableCylinders α), ∃ S, MeasurableSet S ∧ t = MeasureTheory.cylinder ⋯.choose S