∀ {Ω : Type u_1} {ι : Type u_3} {m : MeasurableSpace Ω} [inst : LinearOrder ι] {f : MeasureTheory.Filtration ι m}
  {τ : Ω → WithTop ι} (hτ : MeasureTheory.IsStoppingTime f τ) (s : Set Ω) (i : ι),
  MeasurableSet (s ∩ {ω | τ ω ≤ ↑i}) ↔ MeasurableSet (s ∩ {ω | τ ω ≤ ↑i})