∀ {Ω : Type u_1} {ι : Type u_3} {m : MeasurableSpace Ω} [inst : Preorder ι] {f : MeasureTheory.Filtration ι m}
  {τ : Ω → WithTop ι} (hτ : MeasureTheory.IsStoppingTime f τ) {i : ι}, (∀ (ω : Ω), ↑i ≤ τ ω) → ↑f i ≤ hτ.measurableSpace