∀ {Ω : Type u_1} {m : MeasurableSpace Ω} {X : Ω → ℝ} {μ : MeasureTheory.Measure Ω} {z : ℂ},
  z.re ∈ interior (ProbabilityTheory.integrableExpSet X μ) → AnalyticAt ℂ (ProbabilityTheory.complexMGF X μ) z