∀ {α : Type u_1} {β : Type u_2} {mα : MeasurableSpace α} {mβ : MeasurableSpace β}
  {κ : ProbabilityTheory.Kernel α (β × ℝ)} {ν : ProbabilityTheory.Kernel α β} {f : α × β → ℚ → ℝ}
  [ProbabilityTheory.IsFiniteKernel κ] (hf : ProbabilityTheory.IsRatCondKernelCDF f κ ν) (a : α) (q : ℚ) {s : Set β},
  MeasurableSet s →
    ∫⁻ (b : β) in s, ENNReal.ofReal (↑(ProbabilityTheory.stieltjesOfMeasurableRat f ⋯ (a, b)) ↑q) ∂ν a =
      (κ a) (s ×ˢ Set.Iic ↑q)