∀ {α : Type u_1} {β : Type u_2} {γ : Type u_3} {E : Type u_4} {mα : MeasurableSpace α} {mβ : MeasurableSpace β}
  {mγ : MeasurableSpace γ} [inst : NormedAddCommGroup E] {a : α} {κ : ProbabilityTheory.Kernel α β}
  {η : ProbabilityTheory.Kernel β γ} ⦃f : γ → E⦄,
  MeasureTheory.Integrable f ((η.comp κ) a) → ∀ᵐ (x : β) ∂κ a, MeasureTheory.Integrable f (η x)