∀ {δ : Type u_1} {X : δ → Type u_3} [inst : (i : δ) → MeasurableSpace (X i)] (μ : (i : δ) → MeasureTheory.Measure (X i))
  [inst_1 : DecidableEq δ] [∀ (i : δ), MeasureTheory.SigmaFinite (μ i)] (f : ((i : δ) → X i) → ENNReal),
  Measurable f → ∀ {s t : Finset δ}, Disjoint s t → ∫⋯∫⁻_s ∪ t, f ∂μ = ∫⋯∫⁻_t, ∫⋯∫⁻_s, f ∂μ ∂μ