teorth/PFR
Source indexedlemma · leanprover/lean4:v4.33.0-rc1
ProbabilityTheory.measureMutualInfo_of_not_isFiniteMeasure
PFR.ForMathlib.Entropy.Measure · PFR/ForMathlib/Entropy/Measure.lean:523 to 536
Mathematical statement
Exact Lean statement
lemma measureMutualInfo_of_not_isFiniteMeasure {μ : Measure (S × U)} (h : ¬ IsFiniteMeasure μ) :
Im[μ] = 0Complete declaration
Lean source
Full Lean sourceLean 4
lemma measureMutualInfo_of_not_isFiniteMeasure {μ : Measure (S × U)} (h : ¬ IsFiniteMeasure μ) : Im[μ] = 0 := by rw [measureMutualInfo_def] have h1 : ¬ IsFiniteMeasure (μ.map Prod.fst) := by rw [not_isFiniteMeasure_iff] at h ⊢ rw [← h] exact Measure.map_apply measurable_fst MeasurableSet.univ have h2 : ¬ IsFiniteMeasure (μ.map Prod.snd) := by rw [not_isFiniteMeasure_iff] at h ⊢ rw [← h] exact Measure.map_apply measurable_snd MeasurableSet.univ rw [measureEntropy_of_not_isFiniteMeasure h, measureEntropy_of_not_isFiniteMeasure h1, measureEntropy_of_not_isFiniteMeasure h2] simp