∀ {ι : Type u_1} [inst : LinearOrder ι] [inst_1 : LocallyFiniteOrder ι] [inst_2 : DecidableLE ι] {X : ι → Type u_2}
  [inst_3 : LocallyFiniteOrderBot ι] [inst_4 : (i : ι) → MeasurableSpace (X i)] {a b : ι} (hab : a ≤ b),
  Measurable
    ⇑{ toFun := fun x i => if h : ↑i ≤ a then x.1 ⟨↑i, ⋯⟩ else x.2 ⟨↑i, ⋯⟩,
          invFun := fun x => (fun i => x ⟨↑i, ⋯⟩, fun i => x ⟨↑i, ⋯⟩), left_inv := ⋯, right_inv := ⋯ }.symm