∀ {α : Type u_1} {β : Type u_2} [inst : MeasurableSpace α] [inst_1 : MeasurableSpace β] {μ : MeasureTheory.Measure α}
  {ν : MeasureTheory.Measure β} {s : Set (α × β)},
  MeasurableSet s → (fun x => ν (Prod.mk x ⁻¹' s)) =ᵐ[μ] 0 → (μ.prod ν) s = 0