∀ {α : Type u_1} {mα : MeasurableSpace α} {μ ν : MeasureTheory.Measure α} [MeasureTheory.IsFiniteMeasure μ]
  [MeasureTheory.IsFiniteMeasure ν],
  μ.AbsolutelyContinuous ν →
    MeasureTheory.Integrable (MeasureTheory.llr μ ν) μ →
      μ.real Set.univ * Real.log (μ.real Set.univ / ν.real Set.univ) + ν.real Set.univ - μ.real Set.univ ≤
        (InformationTheory.klDiv μ ν).toReal