∀ {α : Type u_1} {β : Type u_2} {E : Type u_3} [inst : MeasurableSpace α] [inst_1 : MeasurableSpace β]
  {μ : MeasureTheory.Measure α} {ν : MeasureTheory.Measure β} [inst_2 : NormedAddCommGroup E] [MeasureTheory.SFinite ν]
  ⦃f : α × β → E⦄,
  MeasureTheory.StronglyMeasurable f →
    (MeasureTheory.HasFiniteIntegral f (μ.prod ν) ↔
      (∀ᵐ (x : α) ∂μ, MeasureTheory.HasFiniteIntegral (fun y => f (x, y)) ν) ∧
        MeasureTheory.HasFiniteIntegral (fun x => ∫ (y : β), ‖f (x, y)‖ ∂ν) μ)