∀ {β : Type u_2} {γ : Type u_3} {α : Type u_4} [inst : MeasurableSpace β] [inst_1 : MeasurableSpace γ]
  [inst_2 : Pow β γ] [MeasurablePow β γ] {m : MeasurableSpace α} {f : α → β},
  Measurable f → ∀ (c : γ), Measurable fun x => f x ^ c