∀ {E : Type u_1} [inst : NormedAddCommGroup E] [inst_1 : NormedSpace ℝ E] {mE : MeasurableSpace E}
  [OpensMeasurableSpace E] {μ : MeasureTheory.Measure E} [MeasureTheory.IsProbabilityMeasure μ] (L : StrongDual ℝ E)
  {r : ℝ},
  0 < r → μ.real {x | r < |L x|} ≤ 2⁻¹ * r * ‖∫ (t : ℝ) in -2 * r⁻¹..2 * r⁻¹, 1 - MeasureTheory.charFunDual μ (t • L)‖