∀ {ι : Type u_1} {α : ι → Type u_3} [inst : Fintype ι] [inst_1 : (i : ι) → MeasurableSpace (α i)]
  (μ : (i : ι) → MeasureTheory.Measure (α i)) [∀ (i : ι), MeasureTheory.SigmaFinite (μ i)]
  [inst_3 : (i : ι) → MetricSpace (α i)] (x : (i : ι) → α i) {r : ℝ},
  0 ≤ r → (MeasureTheory.Measure.pi μ) (Metric.closedBall x r) = ∏ i, (μ i) (Metric.closedBall (x i) r)