∀ {α : Type u_2} {m : MeasurableSpace α} {δ : Type u_3} [inst : MeasurableSpace δ] [inst_1 : SemilatticeSup α]
  [MeasurableSup₂ α] {f : ℕ → δ → α} {n : ℕ}, (∀ k ≤ n, Measurable (f k)) → Measurable ((Finset.range (n + 1)).sup' ⋯ f)