∀ {α : Type u_1} {β : Type u_2} {m0 : MeasurableSpace α} {μ : MeasureTheory.Measure α} {f : α → β} [inst : Zero β]
  [inst_1 : TopologicalSpace β] (hf : MeasureTheory.FinStronglyMeasurable f μ) (n : ℕ),
  μ (Function.support ⇑(hf.approx n)) < ⊤