have l2 : AEStronglyMeasurable (fun u ↦ 𝓕 ψ (u / c)) volume := by
  apply Continuous.aestronglyMeasurable ; continuity
n : ℕ
A a b c d u x y t σ' : ℝ
ψ✝ Ψ : ℝ → ℂ
F G : ℂ → ℂ
f : ℕ → ℂ
𝕜 : Type
inst✝ : _root_.RCLike 𝕜
ψ : W21
hc : c ≠ 0
l1 : ∀ (C : ℝ), Integrable (fun u => C / (1 + (u / c) ^ 2)) volume
⊢ Integrable (fun u => 𝓕 ψ.toFun (u / c)) volume
n : ℕ
A a b c d u x y t σ' : ℝ
ψ✝ Ψ : ℝ → ℂ
F G : ℂ → ℂ
f : ℕ → ℂ
𝕜 : Type
inst✝ : _root_.RCLike 𝕜
ψ : W21
hc : c ≠ 0
l1 : ∀ (C : ℝ), Integrable (fun u => C / (1 + (u / c) ^ 2)) volume
l2 : AEStronglyMeasurable (fun u => 𝓕 ψ.toFun (u / c)) volume
⊢ Integrable (fun u => 𝓕 ψ.toFun (u / c)) volume