∀ {Ω : Type u_1} {a b : ℝ} {f : ℕ → Ω → ℝ} {N n : ℕ} {ω : Ω},
  a < b →
    MeasureTheory.upperCrossingTime a b f N (n + 1) ω ≠ N →
      MeasureTheory.lowerCrossingTime a b f N n ω < MeasureTheory.upperCrossingTime a b f N (n + 1) ω