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Add lean source and binary files (part 122)
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import OAI.Probability.GaussianReplacement.ActualRow
namespace OAI
open MeasureTheory ProbabilityTheory Set Filter
open scoped ENNReal NNReal RealInnerProductSpace Topology
noncomputable section
namespace CurrentProjection
open InnerProductSpace
open InformationTheory
def conditionalMutualInformation {Z A B : Type*} [MeasurableSpace Z]
[MeasurableSpace A] [MeasurableSpace B] [StandardBorelSpace A] [StandardBorelSpace B]
(P : Measure (Z×(A×B))) [IsFiniteMeasure P] : ℝ≥0∞ := by
classical
exact if h : Nonempty (A×B) then
letI := h
InformationTheory.klDiv P (P.fst ⊗ₘ (P.condKernel.fst ×ₖ P.condKernel.snd))
else 0
lemma kernel_prod_eq_compProd {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] (κ : Kernel Z A) (η : Kernel Z B) [IsSFiniteKernel κ] [IsSFiniteKernel η] :
κ ×ₖ η = κ ⊗ₖ η.comap Prod.fst measurable_fst := by
ext z s hs
rw [Kernel.prod_apply' _ _ _ hs, Kernel.compProd_apply hs]
rfl
lemma compProd_prod_assoc {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] (μ : Measure Z) [SFinite μ] (κ : Kernel Z A) (η : Kernel Z B)
[IsSFiniteKernel κ] [IsSFiniteKernel η] :
(μ ⊗ₘ (κ ×ₖ η)).map MeasurableEquiv.prodAssoc.symm =
(μ ⊗ₘ κ) ⊗ₘ η.comap Prod.fst measurable_fst := by
rw [kernel_prod_eq_compProd, Measure.compProd_assoc]
def swapAssoc {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A] [MeasurableSpace B] :
Z×(A×B) ≃ᵐ (Z×B)×A :=
((MeasurableEquiv.refl Z).prodCongr MeasurableEquiv.prodComm).trans MeasurableEquiv.prodAssoc.symm
lemma compProd_prod_swapAssoc {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] (μ : Measure Z) [SFinite μ] (κ : Kernel Z A) (η : Kernel Z B)
[IsSFiniteKernel κ] [IsSFiniteKernel η] :
(μ ⊗ₘ (κ ×ₖ η)).map swapAssoc = (μ ⊗ₘ η) ⊗ₘ κ.comap Prod.fst measurable_fst := by
change (μ ⊗ₘ (κ ×ₖ η)).map (MeasurableEquiv.prodAssoc.symm ∘ Prod.map id Prod.swap) = _
rw [← Measure.map_map MeasurableEquiv.prodAssoc.symm.measurable
(measurable_id.prodMap measurable_swap), ← Measure.compProd_map measurable_swap,
Kernel.map_prod_swap, compProd_prod_assoc]
lemma fst_map_swapAssoc_compProd {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] (μ : Measure Z) [SFinite μ] (κ : Kernel Z (A×B)) [IsSFiniteKernel κ] :
((μ ⊗ₘ κ).map swapAssoc).fst = μ ⊗ₘ κ.snd := by
rw [Kernel.snd_eq]
rw [Measure.compProd_map measurable_snd]
rw [Measure.fst, Measure.map_map measurable_fst swapAssoc.measurable]
rfl
lemma conditionalKL_chain {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] [StandardBorelSpace A] [Nonempty A]
(μ : Measure Z) [IsProbabilityMeasure μ] (κ : Kernel Z (A×B)) [IsMarkovKernel κ]
(π : Measure B) [IsProbabilityMeasure π] :
klDiv (μ ⊗ₘ κ) (μ ⊗ₘ (κ.fst ×ₖ Kernel.const Z π)) =
klDiv (μ ⊗ₘ κ.snd) (μ.prod π) +
klDiv (μ ⊗ₘ κ) (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) := by
let R := (μ ⊗ₘ κ).map swapAssoc
have hR : R.fst = μ ⊗ₘ κ.snd := fst_map_swapAssoc_compProd μ κ
have hchain := klDiv_compProd_eq_add R.fst (μ.prod π) R.condKernel
(κ.fst.comap Prod.fst measurable_fst)
rw [R.disintegrate R.condKernel, hR] at hchain
have hleft := klDiv_map_equiv (μ ⊗ₘ κ) (μ ⊗ₘ (κ.fst ×ₖ Kernel.const Z π)) swapAssoc
rw [compProd_prod_swapAssoc, Measure.compProd_const] at hleft
have hright := klDiv_map_equiv (μ ⊗ₘ κ) (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) swapAssoc
rw [compProd_prod_swapAssoc] at hright
exact hleft.symm.trans (hchain.trans (congrArg (klDiv (μ ⊗ₘ κ.snd) (μ.prod π) + ·) hright))
def mutualInformation {A B : Type*} [MeasurableSpace A] [MeasurableSpace B]
(P : Measure (A×B)) : ℝ≥0∞ := klDiv P (P.fst.prod P.snd)
lemma fst_map_assoc_compProd {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] (μ : Measure Z) [SFinite μ] (κ : Kernel Z (A×B)) [IsSFiniteKernel κ] :
((μ ⊗ₘ κ).map MeasurableEquiv.prodAssoc.symm).fst = μ ⊗ₘ κ.fst := by
rw [Kernel.fst_eq, Measure.compProd_map measurable_fst, Measure.fst,
Measure.map_map measurable_fst MeasurableEquiv.prodAssoc.symm.measurable]
rfl
lemma mutualInformation_chain {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] [StandardBorelSpace A] [StandardBorelSpace B] [Nonempty A] [Nonempty B]
(P : Measure (Z×(A×B))) [IsProbabilityMeasure P] :
mutualInformation (P.map MeasurableEquiv.prodAssoc.symm) =
mutualInformation (P.map (Prod.map id Prod.snd)) + conditionalMutualInformation P := by
let μ := P.fst
let κ := P.condKernel
let Q := P.map MeasurableEquiv.prodAssoc.symm
let R := P.map (Prod.map id Prod.snd)
let : IsProbabilityMeasure Q := inferInstance
let : IsProbabilityMeasure R := inferInstance
have hP : μ ⊗ₘ κ = P := P.disintegrate P.condKernel
have hQ : Q.fst = μ ⊗ₘ κ.fst := by
change (P.map MeasurableEquiv.prodAssoc.symm).fst = _
rw [← hP]
exact fst_map_assoc_compProd μ κ
have hR : R = μ ⊗ₘ κ.snd := by
rw [Kernel.snd_eq,Measure.compProd_map measurable_snd,hP]
have hRf : R.fst = μ := by rw [hR,Measure.fst_compProd]
have hRs : R.snd = Q.snd := by
dsimp only [R,Q,Measure.snd]
rw [Measure.map_map measurable_snd (measurable_id.prodMap measurable_snd),
Measure.map_map measurable_snd MeasurableEquiv.prodAssoc.symm.measurable]
rfl
have hleft := klDiv_map_equiv P (μ ⊗ₘ (κ.fst ×ₖ Kernel.const Z Q.snd)) MeasurableEquiv.prodAssoc.symm
rw [compProd_prod_assoc] at hleft
have hconst : (Kernel.const Z Q.snd).comap (Prod.fst : Z×A → Z) measurable_fst =
Kernel.const (Z×A) Q.snd := by ext x t ht; rfl
rw [hconst,Measure.compProd_const,← hQ] at hleft
have hc := conditionalKL_chain μ κ Q.snd
have hSmall : klDiv (μ ⊗ₘ κ.snd) (μ.prod Q.snd) = mutualInformation R := by
rw [← hR,← hRf,← hRs]
rfl
rw [hP,hSmall] at hc
have hCM : conditionalMutualInformation P = klDiv P (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) := by
simp only [conditionalMutualInformation,dite_eq_left (inferInstance : Nonempty (A×B))]
rfl
rw [hCM]
exact hleft.trans hc
lemma conditionalMutualInformation_le_entropy {Z A B : Type*} [MeasurableSpace Z] [MeasurableSpace A]
[MeasurableSpace B] [StandardBorelSpace A] [Nonempty A] [Nonempty B]
[Countable B] [MeasurableSingletonClass B]
(P : Measure (Z×(A×B))) [IsProbabilityMeasure P]
(hH : shannonEntropy (P.map MeasurableEquiv.prodAssoc.symm).snd ≠ ∞) :
conditionalMutualInformation P ≠ ∞ ∧
(conditionalMutualInformation P).toReal ≤
(shannonEntropy (P.map MeasurableEquiv.prodAssoc.symm).snd).toReal := by
let : IsProbabilityMeasure (P.map MeasurableEquiv.prodAssoc.symm) :=
inferInstance
have h := countable_information_le_entropy (P.map MeasurableEquiv.prodAssoc.symm) hH
have hle : conditionalMutualInformation P ≤ mutualInformation (P.map MeasurableEquiv.prodAssoc.symm) := by
rw [mutualInformation_chain P]
exact le_add_left le_rfl
exact ⟨ne_top_of_le_ne_top h.1 hle,(ENNReal.toReal_mono h.1 hle).trans h.2⟩
lemma conditionalMutualInformation_compProd {Z A B : Type*} [MeasurableSpace Z]
[MeasurableSpace A] [MeasurableSpace B] [StandardBorelSpace A] [StandardBorelSpace B]
[Nonempty A] [Nonempty B] (μ : Measure Z) [IsFiniteMeasure μ]
(κ : Kernel Z (A×B)) [IsMarkovKernel κ] :
conditionalMutualInformation (μ ⊗ₘ κ) = klDiv (μ ⊗ₘ κ) (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) := by
simp only [conditionalMutualInformation,dite_eq_left (inferInstance : Nonempty (A×B)),Measure.fst_compProd]
congr 1
apply Measure.compProd_congr
filter_upwards [condKernel_compProd μ κ] with z hz
simp only [Kernel.prod_apply,Kernel.fst_apply,Kernel.snd_apply,hz]
lemma conditionalMutualInformation_map_right_le {Z A B C : Type*} [MeasurableSpace Z]
[MeasurableSpace A] [MeasurableSpace B] [MeasurableSpace C]
[StandardBorelSpace A] [StandardBorelSpace B] [StandardBorelSpace C]
[Nonempty A] [Nonempty B] [Nonempty C]
(P : Measure (Z×(A×B))) [IsProbabilityMeasure P] (f : B → C) (hf : Measurable f) :
conditionalMutualInformation (P.map (Prod.map id (Prod.map id f))) ≤
conditionalMutualInformation P := by
let μ := P.fst
let κ := P.condKernel
let g : A×B → A×C := Prod.map id f
have hg : Measurable g := measurable_id.prodMap hf
let : IsMarkovKernel (κ.map g) := Kernel.IsMarkovKernel.map κ hg
have hT : Measurable (Prod.map (id : Z → Z) g) := measurable_id.prodMap hg
have hP : μ ⊗ₘ κ = P := P.disintegrate P.condKernel
have hmap : P.map (Prod.map id g) = μ ⊗ₘ κ.map g := by
rw [Measure.compProd_map hg,hP]
have hfst : (κ.map g).fst = κ.fst := by
rw [Kernel.fst_eq,←Kernel.map_comp_right _ hg measurable_fst,Kernel.fst_eq]
rfl
have hsnd : (κ.map g).snd = κ.snd.map f := by
rw [Kernel.snd_eq,Kernel.snd_eq,←Kernel.map_comp_right _ hg measurable_snd,
←Kernel.map_comp_right _ measurable_snd hf]
rfl
have hRef : μ ⊗ₘ ((κ.map g).fst ×ₖ (κ.map g).snd) =
(μ ⊗ₘ (κ.fst ×ₖ κ.snd)).map (Prod.map id g) := by
have hk : κ.fst ×ₖ κ.snd.map f = (κ.fst ×ₖ κ.snd).map g := by
simpa only [Kernel.map_id] using Kernel.map_prod_map κ.fst κ.snd measurable_id hf
rw [hfst,hsnd,hk,Measure.compProd_map hg]
change conditionalMutualInformation (P.map (Prod.map id g)) ≤ _
have hCM := conditionalMutualInformation_compProd μ (κ.map g)
have hCM' : conditionalMutualInformation (P.map (Prod.map id g)) =
klDiv (P.map (Prod.map id g)) ((μ ⊗ₘ (κ.fst ×ₖ κ.snd)).map (Prod.map id g)) := by
simpa only [←hmap,hRef] using hCM
rw [hCM']
have h := klDiv_map_le P (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) hT
have hCM0 : conditionalMutualInformation P = klDiv P (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) := by
simpa only [hP] using conditionalMutualInformation_compProd μ κ
rwa [hCM0]
lemma rowInformation_eq_conditionalMutualInformation {S W X : Type*}
[MeasurableSpace S] [MeasurableSpace W] [MeasurableSpace X]
[StandardBorelSpace W] [StandardBorelSpace X] [Nonempty W] [Nonempty X]
(P : Measure ((S×W)×X)) [IsProbabilityMeasure P]
(ν : Measure S) (γ : Measure X) [IsProbabilityMeasure ν] [IsProbabilityMeasure γ]
(hInd : (P.map swapLast).fst = ν.prod γ) :
rowInformation P γ = conditionalMutualInformation (P.map MeasurableEquiv.prodAssoc) := by
let Q := P.map (MeasurableEquiv.prodAssoc : (S×W)×X ≃ᵐ S×(W×X))
let : IsProbabilityMeasure Q := inferInstance
have hX : P.snd = γ := by
have h := congrArg Measure.snd hInd
rw [Measure.snd_prod] at h
convert h using 1
simp only [Measure.snd, Measure.fst, Measure.map_map measurable_fst swapLast.measurable,
Measure.map_map measurable_snd (measurable_fst.comp swapLast.measurable)]
rfl
have hQ : Q.map MeasurableEquiv.prodAssoc.symm = P :=
MeasurableEquiv.prodAssoc.map_symm_map
have hR : Q.map (Prod.map id Prod.snd) = ν.prod γ := by
trans (P.map swapLast).fst
· dsimp only [Q,Measure.fst]
rw [Measure.map_map (measurable_id.prodMap measurable_snd)
MeasurableEquiv.prodAssoc.measurable,
Measure.map_map measurable_fst swapLast.measurable]
rfl
· exact hInd
have hc := mutualInformation_chain Q
rw [hQ,hR] at hc
have hzero : mutualInformation (ν.prod γ) = 0 := by
simp [mutualInformation, klDiv_self]
rw [hzero,zero_add] at hc
simpa only [rowInformation,mutualInformation,hX] using hc
lemma conditionalMutualInformation_swap {S A B : Type*}
[MeasurableSpace S] [MeasurableSpace A] [MeasurableSpace B]
[StandardBorelSpace A] [StandardBorelSpace B] [Nonempty A] [Nonempty B]
(P : Measure (S×(A×B))) [IsProbabilityMeasure P] :
conditionalMutualInformation (P.map (Prod.map id Prod.swap)) =
conditionalMutualInformation P := by
let μ := P.fst
let κ := P.condKernel
let e : S×(A×B) ≃ᵐ S×(B×A) :=
(MeasurableEquiv.refl S).prodCongr MeasurableEquiv.prodComm
have hP : μ ⊗ₘ κ = P := P.disintegrate P.condKernel
let : IsMarkovKernel (κ.map Prod.swap) := Kernel.IsMarkovKernel.map κ measurable_swap
have hf : (κ.map Prod.swap).fst = κ.snd := by
rw [Kernel.fst_eq, ← Kernel.map_comp_right _ measurable_swap measurable_fst, Kernel.snd_eq]
rfl
have hs : (κ.map Prod.swap).snd = κ.fst := by
rw [Kernel.snd_eq, ← Kernel.map_comp_right _ measurable_swap measurable_snd, Kernel.fst_eq]
rfl
have href : μ ⊗ₘ ((κ.map Prod.swap).fst ×ₖ (κ.map Prod.swap).snd) =
(μ ⊗ₘ (κ.fst ×ₖ κ.snd)).map e := by
rw [hf,hs, ← Kernel.map_prod_swap, Measure.compProd_map measurable_swap]
rfl
have hQ : μ ⊗ₘ κ.map Prod.swap = P.map (Prod.map id Prod.swap) := by
rw [Measure.compProd_map measurable_swap,hP]
have hcm : conditionalMutualInformation (P.map (Prod.map id Prod.swap)) =
klDiv (P.map (Prod.map id Prod.swap)) ((μ ⊗ₘ (κ.fst ×ₖ κ.snd)).map e) := by
simpa only [hQ,href] using conditionalMutualInformation_compProd μ (κ.map Prod.swap)
have hcm0 : conditionalMutualInformation P = klDiv P (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) := by
simpa only [hP] using conditionalMutualInformation_compProd μ κ
rw [hcm,hcm0]
exact klDiv_map_equiv P (μ ⊗ₘ (κ.fst ×ₖ κ.snd)) e
lemma rowInformation_eq_sourceConditionalInformation {S W X : Type*}
[MeasurableSpace S] [MeasurableSpace W] [MeasurableSpace X]
[StandardBorelSpace W] [StandardBorelSpace X]
(P : Measure ((S×W)×X)) [IsProbabilityMeasure P]
(ν : Measure S) (γ : Measure X) [IsProbabilityMeasure ν] [IsProbabilityMeasure γ]
(hInd : (P.map swapLast).fst = ν.prod γ) :
rowInformation P γ = conditionalMutualInformation
(P.map (fun p => (p.1.1,(p.2,p.1.2)))) := by
let := nonempty_of_isProbabilityMeasure P
let : Nonempty W := ⟨(Classical.choice (inferInstance : Nonempty ((S×W)×X))).1.2⟩
let : Nonempty X := ⟨(Classical.choice (inferInstance : Nonempty ((S×W)×X))).2⟩
let : IsProbabilityMeasure (P.map (MeasurableEquiv.prodAssoc : (S×W)×X ≃ᵐ S×(W×X))) :=
inferInstance
rw [rowInformation_eq_conditionalMutualInformation P ν γ hInd]
have he := conditionalMutualInformation_swap
(P.map (MeasurableEquiv.prodAssoc : (S×W)×X ≃ᵐ S×(W×X)))
have hfun : (Prod.map id Prod.swap ∘
(MeasurableEquiv.prodAssoc : (S×W)×X ≃ᵐ S×(W×X))) =
(fun p : (S×W)×X => (p.1.1,(p.2,p.1.2))) := rfl
simpa only [Measure.map_map (measurable_id.prodMap measurable_swap)
MeasurableEquiv.prodAssoc.measurable, hfun] using he.symm
def actualConditionalRowInformation {d m : ℕ} {W : Type*} [MeasurableSpace W]
[StandardBorelSpace W]
(P : Measure ((Sphere d×W)×Rows m d)) [IsFiniteMeasure P] : ℝ≥0∞ :=
conditionalMutualInformation (P.map (fun p => (p.1.1,(p.2,p.1.2))))
structure ActualRowSourceConclusion {d m r q : ℕ} {W : Type*} [MeasurableSpace W]
[StandardBorelSpace W]
(P : Measure ((Sphere d×W)×Rows m d)) [IsProbabilityMeasure P]
(ρ : W → Measure (Sphere d)) (B D : W → ℝ) : Prop where
row_finite : actualConditionalRowInformation P ≠ ∞
row_le_entropy : (actualConditionalRowInformation P).toReal ≤
(shannonEntropy (P.map swapLast).snd).toReal
conditional_density : ∀ᵐ gw ∂((actualExperiment (r:=r) P).map actualObservation).fst,
((actualExperiment (r:=r) P).map actualObservation).condKernel gw ≪ volume
actual_limit : ∀ᵐ p ∂actualExperiment (r:=r) P,
Tendsto (fun j : ℕ => selectedCube ρ (1/(j:ℝ)) (actualObservation p)) atTop
(𝓝 (selectedExact ρ (actualObservation p)))
smoothed_bound : ∀ δ : ℝ, 0 < δ →
Integrable (fun p => Real.log (1+(selectedCube ρ δ (actualObservation p)).toReal))
(actualExperiment (r:=r) P) ∧
(∫ p, Real.log (1+(selectedCube ρ δ (actualObservation p)).toReal) ∂actualExperiment (r:=r) P) ≤
(actualConditionalRowInformation P).toReal/q +
∫ sw : Sphere d×W, Real.log (1+momentBound 9 d (B sw.2) (D sw.2)) ∂P.fst
exact_integrable : Integrable (fun p => Real.log (1+(selectedExact ρ (actualObservation p)).toReal))
(actualExperiment (r:=r) P)
exact_bound : (∫ p, Real.log (1+(selectedExact ρ (actualObservation p)).toReal) ∂actualExperiment (r:=r) P) ≤
(actualConditionalRowInformation P).toReal/q +
∫ sw : Sphere d×W, Real.log (1+momentBound 9 d (B sw.2) (D sw.2)) ∂P.fst
entropy_bound : (actualConditionalRowInformation P).toReal/q +
∫ sw : Sphere d×W, Real.log (1+momentBound 9 d (B sw.2) (D sw.2)) ∂P.fst ≤
(shannonEntropy (P.map swapLast).snd).toReal/q +
∫ sw : Sphere d×W, Real.log (1+momentBound 9 d (B sw.2) (D sw.2)) ∂P.fst
positive_log_integrable : Integrable (fun p => logPositive (selectedExact ρ (actualObservation p)))
(actualExperiment (r:=r) P)
extended_log_bound : extendedLogExpectation (actualExperiment (r:=r) P)
(fun p => selectedExact ρ (actualObservation p)) ≤
(((actualConditionalRowInformation P).toReal/q +
∫ sw : Sphere d×W, Real.log (1+momentBound 9 d (B sw.2) (D sw.2)) ∂P.fst) : EReal)
theorem actualRowSourceMain {d m r q : ℕ} {W : Type*} [MeasurableSpace W]
[Countable W] [MeasurableSingletonClass W]
(hdim : AdmissibleDimensions d m r q)
(P : Measure ((Sphere d×W)×Rows m d)) [IsProbabilityMeasure P]
(ν : Measure (Sphere d)) [IsProbabilityMeasure ν]
(hInd : (P.map swapLast).fst = ν.prod (gaussianRows m d))
(H : ℝ) (hν : ν ≤ ENNReal.ofReal H • uniformSphere d)
(hEntropy : shannonEntropy (P.map swapLast).snd ≠ ∞)
(ρ : PositiveMessage (P.map swapLast).snd → Measure (Sphere d))
[∀ w, IsFiniteMeasure (ρ w)]
(_hρac : ∀ w, ρ w ≪ uniformSphere d)
(B D : PositiveMessage (P.map swapLast).snd → ℝ)
(hB : ∀ w, 0 < B w) (hD : ∀ w, 0 < D w)
(hgB : ∀ w, LocalGrowth (ρ w) (m+r) (B w))
(hgD : ∀ w, LocalGrowth (ρ w) (d-1) (D w))
(hCI : Integrable (fun sw : Sphere d×W => Real.log (1+momentBound 9 d
(completeFamily (P.map swapLast).snd B 1 sw.2) (completeFamily (P.map swapLast).snd D 1 sw.2))) P.fst) :
ActualRowSourceConclusion (r:=r) (q:=q) P (completeFamily (P.map swapLast).snd ρ 0)
(completeFamily (P.map swapLast).snd B 1) (completeFamily (P.map swapLast).snd D 1) := by
have h := actualRowMain hdim P ν hInd H hν hEntropy ρ _hρac B D hB hD hgB hgD hCI
have hi := rowInformation_eq_sourceConditionalInformation P ν (gaussianRows m d) hInd
refine {
row_finite := by simpa only [actualConditionalRowInformation, ← hi] using h.row_finite
row_le_entropy := by simpa only [actualConditionalRowInformation, ← hi] using h.row_le_entropy
conditional_density := by simpa only [actualConditionalRowInformation, ← hi] using h.conditional_density
actual_limit := by simpa only [actualConditionalRowInformation, ← hi] using h.actual_limit
smoothed_bound := by simpa only [actualConditionalRowInformation, ← hi] using h.smoothed_bound
exact_integrable := by simpa only [actualConditionalRowInformation, ← hi] using h.exact_integrable
exact_bound := by simpa only [actualConditionalRowInformation, ← hi] using h.exact_bound
entropy_bound := by simpa only [actualConditionalRowInformation, ← hi] using h.entropy_bound
positive_log_integrable := by simpa only [actualConditionalRowInformation, ← hi] using h.positive_log_integrable
extended_log_bound := by simpa only [actualConditionalRowInformation, ← hi] using h.extended_log_bound
}
theorem actualRowSourceRefinement {d m : ℕ} {W E : Type*} [MeasurableSpace W]
[MeasurableSpace E] [Countable W] [MeasurableSingletonClass W]
[Countable E] [MeasurableSingletonClass E]
(P : Measure ((Sphere d×W)×Rows m d)) [IsProbabilityMeasure P]
(ν : Measure (Sphere d)) [IsProbabilityMeasure ν]
(hInd : (P.map swapLast).fst = ν.prod (gaussianRows m d))
(e : Sphere d×W → E) (he : Measurable e)
(hEntropy : shannonEntropy
((P.map (fun p => ((p.1.1,(p.1.2,e p.1)),p.2))).map swapLast).snd ≠ ∞) :
actualConditionalRowInformation (P.map (fun p => ((p.1.1,(p.1.2,e p.1)),p.2))) =
actualConditionalRowInformation P := by
let F : (Sphere d×W)×Rows m d → (Sphere d×(W×E))×Rows m d :=
fun p => ((p.1.1,(p.1.2,e p.1)),p.2)
have hF : Measurable F :=
(measurable_fst.fst.prodMk (measurable_fst.snd.prodMk (he.comp measurable_fst))).prodMk measurable_snd
let Q := P.map F
let : IsProbabilityMeasure Q := inferInstance
have hIndQ : (Q.map swapLast).fst = ν.prod (gaussianRows m d) := by
trans (P.map swapLast).fst
· dsimp only [Q,Measure.fst]
rw [Measure.map_map swapLast.measurable hF,
Measure.map_map measurable_fst (swapLast.measurable.comp hF),
Measure.map_map measurable_fst swapLast.measurable]
rfl
· exact hInd
have hiQ := rowInformation_eq_sourceConditionalInformation Q ν (gaussianRows m d) hIndQ
have hi := rowInformation_eq_sourceConditionalInformation P ν (gaussianRows m d) hInd
change actualConditionalRowInformation Q = actualConditionalRowInformation P
calc
_ = rowInformation Q (gaussianRows m d) := hiQ.symm
_ = rowInformation P (gaussianRows m d) := actualRowRefinement P e he hEntropy
_ = _ := hi
def alignedExperiment {d m r : ℕ} {W : Type*} [MeasurableSpace W]
(P : Measure ((Sphere d×W)×Rows m d)) : Measure ((Sphere d×W)×Rows (m+r) d) :=
(actualExperiment (r:=r) P).map (fun p => (p.1.1,Fin.append p.1.2 p.2))
lemma measurable_alignedMap {d m r : ℕ} {W : Type*} [MeasurableSpace W] :
Measurable (fun p : ((Sphere d×W)×Rows m d)×Rows r d => (p.1.1,Fin.append p.1.2 p.2)) :=
measurable_fst.fst.prodMk ((measurable_append (E:=Vector d) m r).comp (measurable_fst.snd.prodMk measurable_snd))
instance alignedExperiment_probability {d m r : ℕ} {W : Type*} [MeasurableSpace W]
(P : Measure ((Sphere d×W)×Rows m d)) [IsProbabilityMeasure P] :
IsProbabilityMeasure (alignedExperiment (r:=r) P) := by
unfold alignedExperiment
infer_instance
def exposedJointMap {d k : ℕ} {W : Type*} (p : (Sphere d×W)×Rows k d) :
(Rows k d×(Fin k → ℝ))×(Sphere d×W) := ((p.2,label p.2 (p.1.1:Vector d)),p.1)
lemma measurable_exposedJointMap {d k : ℕ} {W : Type*} [MeasurableSpace W] :
Measurable (exposedJointMap (d:=d) (k:=k) (W:=W)) := by
have hY : Measurable (fun p : (Sphere d×W)×Rows k d => label p.2 (p.1.1:Vector d)) :=
(measurable_own_label (d:=d) (k:=k)).comp (measurable_snd.prodMk measurable_fst.fst)
exact (measurable_snd.prodMk hY).prodMk measurable_fst
def exposedInformation {d k : ℕ} {W : Type*} [MeasurableSpace W] [StandardBorelSpace W]
(P : Measure ((Sphere d×W)×Rows k d)) [IsFiniteMeasure P] : ℝ≥0∞ :=
conditionalMutualInformation (P.map exposedJointMap)
end CurrentProjection
end
end OAI