∀ {ι : Type u_1} {α : ι → Type u_2} [inst : (i : ι) → MeasurableSpace (α i)] {t : Set ((i : ι) → α i)}
  (ht : t ∈ MeasureTheory.measurableCylinders α),
  t = MeasureTheory.cylinder (MeasureTheory.measurableCylinders.finset ht) (MeasureTheory.measurableCylinders.set ht)