∀ {Ω : Type u_1} {ι : Type u_3} {m : MeasurableSpace Ω} [inst : LinearOrder ι] {f : MeasureTheory.Filtration ι m}
  {τ : Ω → WithTop ι} [inst_1 : TopologicalSpace ι] [OrderTopology ι] [FirstCountableTopology ι]
  (hτ : MeasureTheory.IsStoppingTime f τ) (i : ι), MeasurableSet {ω | ↑i ≤ τ ω}