teorth/PFR
Source indexedlemma · leanprover/lean4:v4.33.0-rc1
ProbabilityTheory.Kernel.entropy_fst_sub_mutualInfo_le_entropy_map_mul'
PFR.ForMathlib.Entropy.Kernel.Group · PFR/ForMathlib/Entropy/Kernel/Group.lean:76 to 85
Mathematical statement
Exact Lean statement
@[to_additive]
lemma entropy_fst_sub_mutualInfo_le_entropy_map_mul'
(κ : Kernel T (G × G)) [IsZeroOrMarkovKernel κ] (μ : Measure T) [IsZeroOrProbabilityMeasure μ]
[FiniteSupport μ] (hκ : AEFiniteKernelSupport κ μ) :
Hk[fst κ, μ] - Ik[κ, μ] ≤ Hk[map κ (fun p ↦ p.2 * p.1), μ]Complete declaration
Lean source
Full Lean sourceLean 4
@[to_additive]lemma entropy_fst_sub_mutualInfo_le_entropy_map_mul' (κ : Kernel T (G × G)) [IsZeroOrMarkovKernel κ] (μ : Measure T) [IsZeroOrProbabilityMeasure μ] [FiniteSupport μ] (hκ : AEFiniteKernelSupport κ μ) : Hk[fst κ, μ] - Ik[κ, μ] ≤ Hk[map κ (fun p ↦ p.2 * p.1), μ] := by have h := entropy_snd_sub_mutualInfo_le_entropy_map_mul (swapRight κ) μ hκ.swapRight simp only [snd_swapRight, mutualInfo_swapRight, map_swapRight] at h refine h.trans_eq ?_ have : (fun p : G × G ↦ p.1 * p.2) ∘ Prod.swap = (fun p ↦ p.2 * p.1) := rfl simp_rw [this]