∀ {E : Type u_1} [inst : NormedAddCommGroup E] [inst_1 : NormedSpace ℂ E] {V : Type u_2} {W : Type u_3}
  [inst_2 : NormedAddCommGroup V] [inst_3 : NormedSpace ℝ V] [inst_4 : NormedAddCommGroup W] [inst_5 : NormedSpace ℝ W]
  (L : V →L[ℝ] W →L[ℝ] ℝ) {f : V → E} [inst_6 : MeasurableSpace V] [BorelSpace V] [SecondCountableTopology V]
  {μ : MeasureTheory.Measure V},
  MeasureTheory.Integrable f μ →
    MeasureTheory.Integrable (fun v => ‖v‖ * ‖f v‖) μ →
      fderiv ℝ (VectorFourier.fourierIntegral Real.fourierChar μ L.toLinearMap₁₂ f) =
        VectorFourier.fourierIntegral Real.fourierChar μ L.toLinearMap₁₂ (VectorFourier.fourierSMulRight L f)