roseking's picture
Add lean source and binary files (part 61)
ea76aac verified
Raw History Blame Contribute Delete
42.9 kB
import Mathlib
import OAI.Computability.MaxCut.Encoding.SelectedPolicies
namespace OAI
namespace MaxCutGames.Decoder.VisibleTransfer
open MaxCutGames.Foundations.Games
open scoped BigOperators
noncomputable section
variable {Ω D : Type*} [Fintype Ω] [Fintype D]
/-- The part of an event in one actual visible-data fiber. -/
def fiberEvent (observe : Ω → D) (d : D) (event : Ω → Bool) : Ω → Bool := by
classical
exact fun x => decide (observe x = d) && event x
def fiberMass (μ : FiniteDistribution Ω) (observe : Ω → D)
(d : D) (event : Ω → Bool) : ℝ :=
μ.probability (fiberEvent observe d event)
omit [Fintype D] in
theorem fiberMass_nonnegative (μ : FiniteDistribution Ω) (observe : Ω → D)
(d : D) (event : Ω → Bool) : 0 ≤ fiberMass μ observe d event :=
μ.probability_nonnegative _
omit [Fintype D] in
theorem fiberMass_mono (μ : FiniteDistribution Ω) (observe : Ω → D)
(d : D) {event event' : Ω → Bool}
(h : ∀ x, event x = true → event' x = true) :
fiberMass μ observe d event ≤ fiberMass μ observe d event' := by
apply μ.probability_mono
intro x hx
simp only [fiberEvent, Bool.and_eq_true, decide_eq_true_eq] at hx ⊢
exact ⟨hx.1, h x hx.2⟩
theorem sum_fiberMass (μ : FiniteDistribution Ω) (observe : Ω → D)
(event : Ω → Bool) :
∑ d, fiberMass μ observe d event = μ.probability event := by
classical
unfold fiberMass FiniteDistribution.probability fiberEvent
rw [Finset.sum_comm]
apply Finset.sum_congr rfl
intro x _
cases event x <;> simp
theorem observation_weight (μ : FiniteDistribution Ω) (observe : Ω → D) (d : D) :
(μ.pushforward observe).weight d = fiberMass μ observe d (fun _ => true) := by
classical
simp [FiniteDistribution.pushforward, fiberMass, FiniteDistribution.probability,
fiberEvent]
/-- Positive projected column-slice mass and sufficient conditional target
agreement. Both quantities are computed after fixing actual visible data. -/
def visibleWitness (μ : FiniteDistribution Ω) (observe : Ω → D)
(slice targetHit : Ω → Bool) (threshold : ℝ) (d : D) : Bool := by
classical
exact decide (0 < fiberMass μ observe d slice ∧
threshold * fiberMass μ observe d slice ≤
fiberMass μ observe d (fun x => slice x && targetHit x))
/-- The positive part of the witness margin is paid for by the probability of
the actual observed data, rather than by the larger hidden sample space. -/
theorem witness_margin_le_visible_probability
(μ : FiniteDistribution Ω) (observe : Ω → D)
(slice targetHit : Ω → Bool) (threshold : ℝ) (hthreshold : 0 ≤ threshold) :
μ.probability (fun x => slice x && targetHit x) - threshold * μ.probability slice ≤
(μ.pushforward observe).probability (visibleWitness μ observe slice targetHit threshold) := by
classical
have pointwise (d : D) :
fiberMass μ observe d (fun x => slice x && targetHit x) -
threshold * fiberMass μ observe d slice ≤
if visibleWitness μ observe slice targetHit threshold d then
(μ.pushforward observe).weight d else 0 := by
have hs := fiberMass_nonnegative μ observe d slice
have hm := fiberMass_nonnegative μ observe d (fun x => slice x && targetHit x)
have hms : fiberMass μ observe d (fun x => slice x && targetHit x) ≤
fiberMass μ observe d slice := by
apply fiberMass_mono
intro x hx
simp only [Bool.and_eq_true] at hx
exact hx.1
have hmo : fiberMass μ observe d (fun x => slice x && targetHit x) ≤
(μ.pushforward observe).weight d := by
rw [observation_weight]
exact fiberMass_mono μ observe d (fun _ _ => rfl)
by_cases hgood : visibleWitness μ observe slice targetHit threshold d = true
· simp only [hgood, ↓reduceIte]
exact (sub_le_self _ (mul_nonneg hthreshold hs)).trans hmo
· simp only [hgood, Bool.false_eq_true, ↓reduceIte]
by_cases hpos : 0 < fiberMass μ observe d slice
· have hnot : ¬ threshold * fiberMass μ observe d slice ≤
fiberMass μ observe d (fun x => slice x && targetHit x) := by
intro hle
exact hgood (by simp [visibleWitness, hpos, hle])
linarith
· have hzero : fiberMass μ observe d slice = 0 := le_antisymm (le_of_not_gt hpos) hs
rw [hzero, mul_zero, sub_zero]
exact hms.trans_eq hzero
have hsum := Finset.sum_le_sum (s := Finset.univ) fun d _ => pointwise d
simpa only [Finset.sum_sub_distrib, ← Finset.mul_sum, sum_fiberMass,
FiniteDistribution.probability] using hsum
omit [Fintype D] in
/-- On every selected datum the conditional distribution is defined on an
actual nonempty positive-mass slice and has the promised target agreement. -/
theorem visibleWitness_conditional
(μ : FiniteDistribution Ω) (observe : Ω → D)
(slice targetHit : Ω → Bool) (threshold : ℝ) (d : D)
(h : visibleWitness μ observe slice targetHit threshold d = true) :
∃ hpositive : 0 < μ.probability (fiberEvent observe d slice),
threshold ≤ (μ.condition (fiberEvent observe d slice) hpositive).probability targetHit := by
classical
have hh : 0 < fiberMass μ observe d slice ∧
threshold * fiberMass μ observe d slice ≤
fiberMass μ observe d (fun x => slice x && targetHit x) := by
simpa only [visibleWitness, decide_eq_true_eq] using h
unfold fiberMass at hh
refine ⟨hh.1, ?_⟩
rw [FiniteDistribution.probability_condition]
have hsame : (fun x => fiberEvent observe d slice x && targetHit x) =
fiberEvent observe d (fun x => slice x && targetHit x) := by
funext x
simp [fiberEvent, Bool.and_assoc]
rw [hsame]
exact (le_div_iff₀ hh.1).mpr hh.2
omit [Fintype D] in
/-- Goodness is inherited from any event whose membership requires good
visible advice. Positivity supplies an actual supporting hidden sample. -/
theorem visibleWitness_good
(μ : FiniteDistribution Ω) (observe : Ω → D)
(slice targetHit : Ω → Bool) (threshold : ℝ)
(good : D → Prop) (hslice : ∀ x, slice x = true → good (observe x))
(d : D) (h : visibleWitness μ observe slice targetHit threshold d = true) :
good d := by
classical
have hpos : 0 < fiberMass μ observe d slice := by
have hh := of_decide_eq_true h
exact hh.1
by_contra hbad
have hempty : fiberEvent observe d slice = fun _ => false := by
funext x
apply Bool.eq_false_iff.mpr
intro hx
have hh : observe x = d ∧ slice x = true := by
simpa only [fiberEvent, Bool.and_eq_true, decide_eq_true_eq] using hx
exact hbad (hh.1 ▸ hslice x hh.2)
unfold fiberMass at hpos
rw [hempty, FiniteDistribution.probability_false] at hpos
exact (lt_irrefl 0) hpos
/-- A pair of full-table event probabilities transfers with error
`(1 + threshold) * TV`. This estimate precedes all conditioning. -/
theorem margin_transfer (μ ν : FiniteDistribution Ω)
(slice targetHit : Ω → Bool) (threshold : ℝ) (hthreshold : 0 ≤ threshold) :
μ.probability (fun x => slice x && targetHit x) - threshold * μ.probability slice -
(1 + threshold) * μ.totalVariation ν ≤
ν.probability (fun x => slice x && targetHit x) - threshold * ν.probability slice := by
have hm := μ.probability_sub_le_totalVariation ν (fun x => slice x && targetHit x)
have hs := ν.probability_sub_le_totalVariation μ slice
rw [FiniteDistribution.totalVariation_comm] at hs
have hscaled := mul_le_mul_of_nonneg_left hs hthreshold
nlinarith
/-- The whole-table comparison and the exact finite disintegration combine
without any assumption on conditional projection laws. -/
theorem wholeTable_transfer_to_visibleWitness
{Γ : Type*} [Fintype Γ]
(unrestricted : FiniteDistribution Ω) (actual : FiniteDistribution Γ)
(pad : Γ → Ω) (observe : Γ → D) (slice targetHit : Ω → Bool)
(threshold γ : ℝ) (hthreshold : 0 ≤ threshold)
(hmargin : γ ≤
unrestricted.probability (fun x => slice x && targetHit x) -
threshold * unrestricted.probability slice -
(1 + threshold) * unrestricted.totalVariation (actual.pushforward pad)) :
γ ≤ (actual.pushforward observe).probability
(visibleWitness actual observe (fun x => slice (pad x))
(fun x => targetHit (pad x)) threshold) := by
have transferred := margin_transfer unrestricted (actual.pushforward pad)
slice targetHit threshold hthreshold
simp only [FiniteDistribution.probability_pushforward] at transferred
exact (hmargin.trans transferred).trans
(witness_margin_le_visible_probability actual observe
(fun x => slice (pad x)) (fun x => targetHit (pad x)) threshold hthreshold)
theorem projected_witness_mass
{Γ : Type*} [Fintype Γ]
(unrestricted : FiniteDistribution Ω) (actual : FiniteDistribution Γ)
(pad : Γ → Ω) (observe : Γ → D) (slice targetHit : Ω → Bool)
(α g₀ c : ℝ) (hα : 0 ≤ α)
(hslice : g₀ * c ≤ unrestricted.probability slice)
(hagreement : (α / 2) * unrestricted.probability slice ≤
unrestricted.probability (fun x => slice x && targetHit x))
(herror : (1 + α / 4) * unrestricted.totalVariation (actual.pushforward pad) ≤
α * g₀ * c / 8) :
α * g₀ * c / 8 ≤ (actual.pushforward observe).probability
(visibleWitness actual observe (fun x => slice (pad x))
(fun x => targetHit (pad x)) (α / 4)) := by
apply wholeTable_transfer_to_visibleWitness unrestricted actual pad observe slice targetHit
(α / 4) (α * g₀ * c / 8) (by positivity)
have hscaled := mul_le_mul_of_nonneg_left hslice (show 0 ≤ α / 4 by positivity)
nlinarith
end
end MaxCutGames.Decoder.VisibleTransfer
namespace MaxCutGames.Decoder.UniformFibers
open Foundations.Games
open scoped BigOperators Classical
noncomputable section
variable {Ω D Y : Type*}
def selectedFiberEquiv (observe : Ω → D) (d : D) (slice : Ω → Bool)
(e : Y ≃ {x : Ω // observe x = d}) :
{x : Ω // VisibleTransfer.fiberEvent observe d slice x = true} ≃
{y : Y // slice (e y).val = true} where
toFun x := by
have hx : observe x.val = d ∧ slice x.val = true := by
simpa only [VisibleTransfer.fiberEvent, Bool.and_eq_true, decide_eq_true_eq] using x.property
refine ⟨e.symm ⟨x.val, hx.1⟩, ?_⟩
simpa only [Equiv.apply_symm_apply] using hx.2
invFun y := ⟨(e y.val).val, by
simp only [VisibleTransfer.fiberEvent, Bool.and_eq_true, decide_eq_true_eq]
exact ⟨(e y.val).property, y.property⟩⟩
left_inv x := by
apply Subtype.ext
dsimp
simp only [Equiv.apply_symm_apply]
right_inv y := by
apply Subtype.ext
exact e.symm_apply_apply y.val
theorem selectedFiberEquiv_point (observe : Ω → D) (d : D) (slice : Ω → Bool)
(e : Y ≃ {x : Ω // observe x = d})
(x : {x : Ω // VisibleTransfer.fiberEvent observe d slice x = true}) :
(e (selectedFiberEquiv observe d slice e x).val).val = x.val := by
exact congrArg Subtype.val (e.apply_symm_apply _)
/-- Conditioning after fixing the complete datum and the selected column
event leaves precisely the uniform restricted private fiber. -/
theorem conditional_probability [Fintype Ω] [Fintype Y]
(μ : FiniteDistribution Ω) (observe : Ω → D) (d : D)
(slice event : Ω → Bool)
(positive : 0 < μ.probability (VisibleTransfer.fiberEvent observe d slice))
(c : ℝ) (hconstant : ∀ x, observe x = d → μ.weight x = c)
(e : Y ≃ {x : Ω // observe x = d}) :
(μ.condition (VisibleTransfer.fiberEvent observe d slice) positive).probability event =
𝔼 y : {y : Y // slice (e y).val = true},
if event (e y.val).val then (1 : ℝ) else 0 := by
apply UniformConditioning.condition_probability_equiv μ
(VisibleTransfer.fiberEvent observe d slice) event positive c
(fun x hx => hconstant x (by
have h : observe x = d ∧ slice x = true := by
simpa only [VisibleTransfer.fiberEvent, Bool.and_eq_true, decide_eq_true_eq] using hx
exact h.1))
(selectedFiberEquiv observe d slice e)
(fun y => event (e y.val).val)
intro x
rw [selectedFiberEquiv_point]
end
end MaxCutGames.Decoder.UniformFibers
/-! The complete-data conditional law of the actual projected experiment.
The residual private matrix is uniform even when the occurrence law is
weighted and the public row map has deficient rank. -/
namespace MaxCutGames.Decoder.ActualConditionalLaw
open Integration.BinaryLinear Reduction ActualSource Foundations.Games
open scoped BigOperators Classical
noncomputable section
attribute [local instance] Fintype.ofFinite
local instance homFintype {D F : Type*}
[AddCommGroup D] [Module F2 D] [AddCommGroup F] [Module F2 F]
[Fintype D] [Fintype F] : Fintype (D →ₗ[F2] F) :=
Fintype.ofInjective (fun M : D →ₗ[F2] F => (M : D → F)) DFunLike.coe_injective
section Conditioning
variable {k : ℕ} {Id K W R : Type}
[Fintype Id] [AddCommGroup K] [Module F2 K] [Fintype K]
[AddCommGroup W] [Module F2 W] [Fintype W]
[AddCommGroup R] [Module F2 R] [Fintype R]
theorem probability_condition_complete
(occurrences : FiniteDistribution (Fin k → Id))
(publicLaw : FiniteDistribution (K →ₗ[F2] R))
(β : ℝ) (hβ : 0 ≤ β) (hβ' : β ≤ 1)
(d : AdviceLaw.CompleteData k Id K W R)
(slice event : AdviceLaw.FullSeed k Id K W R → Bool)
(positive : 0 < (AdviceLaw.fullSeedLaw (V := K × W) occurrences publicLaw β hβ hβ').probability
(VisibleTransfer.fiberEvent AdviceLaw.completeObserve d slice)) :
((AdviceLaw.fullSeedLaw (V := K × W) occurrences publicLaw β hβ hβ').condition
(VisibleTransfer.fiberEvent AdviceLaw.completeObserve d slice) positive).probability event =
𝔼 N : {N : AdviceLaw.PrivateMap d // slice (AdviceLaw.completeAssemble d N) = true},
if event (AdviceLaw.completeAssemble d N.val) then (1 : ℝ) else 0 := by
exact UniformFibers.conditional_probability
(AdviceLaw.fullSeedLaw (V := K × W) occurrences publicLaw β hβ hβ')
AdviceLaw.completeObserve d slice event positive
(AdviceLaw.completeWeight occurrences publicLaw β d)
(AdviceLaw.fullSeed_weight_fiber occurrences publicLaw β hβ hβ' d)
(AdviceLaw.completeFiberEquiv d)
end Conditioning
variable {k s d r : ℕ}
/-- Both provers' answers, and their equality predicate, are fixed on the
complete observation fiber. Only the hidden matrix varies within that fiber. -/
theorem observedAgreement_completeDraw (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(good : VisiblePolicies.LeftInput S k s d (Vector r) → VisiblePolicies.ResponseWitness k → Prop)
(data : AdviceLaw.CompleteData k (Fin S.occurrences) (Alphabet s) (Vector d) (Vector r))
(N N' : AdviceLaw.PrivateMap data) :
VisiblePolicies.observedAgreement S labeling good (AdviceLaw.completeDraw data N) =
VisiblePolicies.observedAgreement S labeling good (AdviceLaw.completeDraw data N') := by
unfold VisiblePolicies.observedAgreement
rw [AdviceLaw.completeDraw_left, AdviceLaw.completeDraw_left]
simp only [AdviceExperiment.rightObservation, AdviceLaw.completeDraw_rows]
rfl
def datumAgreement (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(good : VisiblePolicies.LeftInput S k s d (Vector r) → VisiblePolicies.ResponseWitness k → Prop)
(data : AdviceLaw.CompleteData k (Fin S.occurrences) (Alphabet s) (Vector d) (Vector r)) : ℝ :=
VisiblePolicies.observedAgreement S labeling good (AdviceLaw.completeDraw data 0)
theorem datumAgreement_nonneg (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(good : VisiblePolicies.LeftInput S k s d (Vector r) → VisiblePolicies.ResponseWitness k → Prop)
(data : AdviceLaw.CompleteData k (Fin S.occurrences) (Alphabet s) (Vector d) (Vector r)) :
0 ≤ datumAgreement S labeling good data :=
FiniteDistribution.probability_nonnegative _ _
/-- The actual success observable factors through the complete visible datum;
this justifies integrating a lower bound over visible-witness probability. -/
theorem observedAgreement_seed (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(good : VisiblePolicies.LeftInput S k s d (Vector r) → VisiblePolicies.ResponseWitness k → Prop)
(x : AdviceLaw.FullSeed k (Fin S.occurrences) (Alphabet s) (Vector d) (Vector r)) :
VisiblePolicies.observedAgreement S labeling good
(AdviceLaw.seedToActualDraw x.1.1 x.1.2 x.2) =
datumAgreement S labeling good (AdviceLaw.completeObserve x) := by
let y := AdviceLaw.fullSeedCoordinatesEquiv x
have hx : AdviceLaw.completeAssemble y.1 y.2 = x :=
AdviceLaw.fullSeedCoordinatesEquiv.symm_apply_apply x
rw [← hx, AdviceLaw.completeDraw_seed]
change VisiblePolicies.observedAgreement S labeling good (AdviceLaw.completeDraw y.1 y.2) =
datumAgreement S labeling good (AdviceLaw.completeObserve (AdviceLaw.completeAssemble y.1 y.2))
rw [AdviceLaw.completeObserve_assemble]
exact observedAgreement_completeDraw S labeling good y.1 y.2 0
end
end MaxCutGames.Decoder.ActualConditionalLaw
/-!
# Actual conditional selected-fiber agreement
The selected event is the full-table event used by the total-variation
comparison. On a positive complete-data fiber it becomes the uniform actual
affine row/column slice. The selector is fixed by the left observation; the
extra complete data and a supporting matrix occur only in this analysis.
-/
noncomputable section
namespace MaxCutGames.Decoder.SelectedFiberLaw
open MaxCutGames.Integration.BinaryLinear MaxCutGames.Reduction MaxCutGames.Soundness
open MaxCutGames.Inverse MaxCutGames.Foundations.Games
open ActualSource VisiblePolicies SelectedPolicies MatrixCoordinates ActualSeedEvents
open scoped BigOperators Classical
attribute [local instance] Classical.propDecidable
attribute [local instance] Fintype.ofFinite
local instance homFintype {D F : Type*}
[AddCommGroup D] [Module F2 D] [AddCommGroup F] [Module F2 F]
[Fintype D] [Fintype F] : Fintype (D →ₗ[F2] F) :=
Fintype.ofInjective (fun M : D →ₗ[F2] F => (M : D → F)) DFunLike.coe_injective
/-- The universe finset is independent of the chosen finite enumeration.
The instances are explicit so elaboration need not unfold either enumeration. -/
private theorem univ_congr_inline_SelectedFiberLaw {X : Type*} (i j : Fintype X) :
@Finset.univ X i = @Finset.univ X j := by
cases Subsingleton.elim i j
rfl
private theorem condition_prob_enumeration {Ω : Type} (i j : Fintype Ω)
(μ : @FiniteDistribution Ω i) (ν : @FiniteDistribution Ω j)
(hw : ∀ x, @FiniteDistribution.weight Ω i μ x = @FiniteDistribution.weight Ω j ν x) (slice event : Ω → Bool)
(hm : 0 < @FiniteDistribution.probability Ω i μ slice)
(hn : 0 < @FiniteDistribution.probability Ω j ν slice) :
@FiniteDistribution.probability Ω i (@FiniteDistribution.condition Ω i μ slice hm) event =
@FiniteDistribution.probability Ω j (@FiniteDistribution.condition Ω j ν slice hn) event := by
cases Subsingleton.elim i j
let : Fintype Ω := i
have he : μ = ν := FiniteDistribution.eq_of_weight_eq hw
subst ν
rfl
variable {k s d r : ℕ}
def datumLeft (S : Source) (data : Datum S k s d r) : LeftInput S k s d (Vector r) :=
AdviceExperiment.leftObservation (ActualGame.rhs S) (AdviceLaw.completeDraw data 0)
def datumMatrix (S : Source) (data : Datum S k s d r) (N : AdviceLaw.PrivateMap data) :=
(AdviceLaw.completeDraw data N).hiddenMatrix
def datumProjection (S : Source) (data : Datum S k s d r) :=
AdviceExperiment.projection (ActualGame.rhs S) (AdviceLaw.completeDraw data 0)
theorem datumLeft_eq (S : Source) (data : Datum S k s d r) (N : AdviceLaw.PrivateMap data) :
AdviceExperiment.leftObservation (ActualGame.rhs S) (AdviceLaw.completeDraw data N) =
datumLeft S data := by
unfold datumLeft
rw [AdviceLaw.completeDraw_left, AdviceLaw.completeDraw_left]
theorem datumMatrix_rows (S : Source) (data : Datum S k s d r) (N : AdviceLaw.PrivateMap data) :
data.1.2.comp (datumMatrix S data N) = data.2.2.2.val :=
AdviceLaw.completeDraw_rows data N
theorem datumMatrix_rowAdvice (S : Source) (data : Datum S k s d r)
(N : AdviceLaw.PrivateMap data) :
RowErasureMatrix.rowAdvice (LinearMap.toMatrix' data.1.2)
(mapEquiv k s ((datumMatrix S data N).comp (datumProjection S data))) =
mapEquiv k r (datumLeft S data).rows := by
rw [← mapEquiv_rowAdvice]
change mapEquiv k r ((data.1.2.comp (datumMatrix S data N)).comp (datumProjection S data)) =
mapEquiv k r ((data.1.2.comp (datumMatrix S data 0)).comp (datumProjection S data))
rw [datumMatrix_rows, datumMatrix_rows] ; rfl
/-- Every event membership uses the same selected normalized witness on the
entire complete-data fiber. -/
theorem slice_assemble_iff (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (hα : 0 < α) (hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(data : Datum S k s d r) (hgood : GoodAdvice S labeling α (datumLeft S data))
(N : AdviceLaw.PrivateMap data) :
slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true ↔
mapEquiv k s ((datumMatrix S data N).comp (datumProjection S data)) ∈
(normalizedDescription S labeling α hα hsmall (datumLeft S data) hgood).toSlice.points := by
rw [slice_eq_selectedEvent]
change decide ((RowErasureMatrix.family s (1 + 2 * k) r).selectedEvent
(fullTable S labeling (AdviceExperiment.leftObservation (ActualGame.rhs S)
(AdviceLaw.completeDraw data N))) α (LinearMap.toMatrix' data.1.2)
(mapEquiv k s ((datumMatrix S data N).comp (datumProjection S data)))) = true ↔ _
rw [datumLeft_eq, decide_eq_true_eq]
exact SelectedDecoding.selectedEvent_iff_normalized S labeling α hα hsmall
(datumLeft S data) hgood _ (datumMatrix_rowAdvice S data N)
/-- On the selected event, the actual full-table target-hit predicate equals
projected affine equality with the very same normalized coefficient/intercept. -/
theorem target_assemble_iff (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (hα : 0 < α) (hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(data : Datum S k s d r) (hgood : GoodAdvice S labeling α (datumLeft S data))
(N : AdviceLaw.PrivateMap data)
(hN : slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true) :
targetHit S k s d r labeling α (AdviceLaw.completeAssemble data N) = true ↔
TableKeysRestoration.projectedAnswer S k s d labeling (PaddedLaw.choiceMask data.2.1)
(RawPrivateTable.supported (PaddedLaw.choiceMask data.2.1) (ActualGame.names S)
data.1.1 (PaddedLaw.choiceSlots data.2.1)) ((datumMatrix S data N).prod data.2.2.1) =
datumMatrix S data N (datumProjection S data
(normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood).coefficient) +
(normalizedDescription S labeling α hα hsmall (datumLeft S data) hgood).intercept := by
have hp := (slice_assemble_iff S labeling α hα hsmall data hgood N).mp hN
rw [targetHit_eq_selectedMatch]
change decide ((RowErasureMatrix.family s (1 + 2 * k) r).selectedMatch
(fullTable S labeling (AdviceExperiment.leftObservation (ActualGame.rhs S)
(AdviceLaw.completeDraw data N))) α (LinearMap.toMatrix' data.1.2)
(mapEquiv k s ((datumMatrix S data N).comp (datumProjection S data)))) = true ↔ _
rw [datumLeft_eq, decide_eq_true_eq]
refine (SelectedDecoding.selectedMatch_iff_normalized S labeling α hα hsmall
(datumLeft S data) hgood _ (datumMatrix_rowAdvice S data N)).trans ?_
have hp' : mapEquiv k s ((datumMatrix S data N).comp (datumProjection S data)) ∈
(RowErasureMatrix.family s (1 + 2 * k) r).points
(normalizedDescription S labeling α hα hsmall (datumLeft S data) hgood) := hp
simp only [hp', true_and, LinearEquiv.symm_apply_apply]
rw [show fullTable S labeling (datumLeft S data)
(mapEquiv k s ((datumMatrix S data N).comp (datumProjection S data))) =
TableKeysRestoration.projectedAnswer S k s d labeling (PaddedLaw.choiceMask data.2.1)
(RawPrivateTable.supported (PaddedLaw.choiceMask data.2.1) (ActualGame.names S)
data.1.1 (PaddedLaw.choiceSlots data.2.1)) ((datumMatrix S data N).prod data.2.2.1) from
ProjectedColumnSlice.fullTable_padded S labeling (AdviceLaw.completeDraw data 0) (datumMatrix S data N)] ; rfl
/-- Positive mass supplies a supporting private coordinate in the selected
fiber; neither a hidden matrix nor good advice is an additional premise. -/
theorem exists_selected_private (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α β : ℝ) (hβ : 0 ≤ β) (hβ' : β ≤ 1) (data : Datum S k s d r)
(positive : 0 < (law S k s d r β hβ hβ').probability
(VisibleTransfer.fiberEvent AdviceLaw.completeObserve data (slice S k s d r labeling α))) :
∃ N : AdviceLaw.PrivateMap data,
slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true := by
have hex : ∃ x : Seed S k s d r,
VisibleTransfer.fiberEvent AdviceLaw.completeObserve data (slice S k s d r labeling α) x = true := by
by_contra hn
have he : VisibleTransfer.fiberEvent AdviceLaw.completeObserve data
(slice S k s d r labeling α) = fun _ => false := by
funext x
apply Bool.eq_false_iff.mpr
intro hx
exact hn ⟨x, hx⟩
rw [he, FiniteDistribution.probability_false] at positive
exact (lt_irrefl 0) positive
obtain ⟨x, hx⟩ := hex
have hx' : AdviceLaw.completeObserve x = data ∧ slice S k s d r labeling α x = true := by
simpa only [VisibleTransfer.fiberEvent, Bool.and_eq_true, decide_eq_true_eq] using hx
let N := (AdviceLaw.completeFiberEquiv data).symm ⟨x, hx'.1⟩
have he : AdviceLaw.completeAssemble data N = x :=
congrArg Subtype.val ((AdviceLaw.completeFiberEquiv data).apply_symm_apply ⟨x, hx'.1⟩)
exact ⟨N, he.symm ▸ hx'.2⟩
theorem good_of_selected_private (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (data : Datum S k s d r) (N : AdviceLaw.PrivateMap data)
(hN : slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true) :
GoodAdvice S labeling α (datumLeft S data) := by
have hg := slice_good S k s d r labeling α (AdviceLaw.completeAssemble data N) hN
change GoodAdvice S labeling α
(AdviceExperiment.leftObservation (ActualGame.rhs S) (AdviceLaw.completeDraw data N)) at hg
rw [datumLeft_eq] at hg
exact hg
/-- The actual selected private coordinates are in bijection with the complete
projected affine slice. The supporting point is used only to state its column
equations; the canonical visible base still defines the private coordinates. -/
def selectedPrivateEquiv (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (hα : 0 < α) (hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(data : Datum S k s d r) (hgood : GoodAdvice S labeling α (datumLeft S data))
(Nstar : AdviceLaw.PrivateMap data)
(hstar : slice S k s d r labeling α (AdviceLaw.completeAssemble data Nstar) = true) :
{N : AdviceLaw.PrivateMap data //
slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true} ≃
RowErasureSliceQuotient.AffineSlice data.1.2
((normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood).columns.map
(datumProjection S data)) (datumMatrix S data Nstar) := by
let D := normalizedDescription S labeling α hα hsmall (datumLeft S data) hgood
let e := AdviceFibers.rowFiberEquiv data.1.2 data.2.2.2.val
(AdviceFibers.observedBase data.1.2 data.2.2.2)
(AdviceFibers.observedBase_property data.1.2 data.2.2.2)
have hs : mapEquiv k s ((datumMatrix S data Nstar).comp (datumProjection S data)) ∈ D.toSlice.points :=
(slice_assemble_iff S labeling α hα hsmall data hgood Nstar).mp hstar
have hrow (N : AdviceLaw.PrivateMap data) :
data.1.2.comp (datumMatrix S data N) = data.1.2.comp (datumMatrix S data Nstar) := by
rw [datumMatrix_rows, datumMatrix_rows]
let lift := fun M : RowErasureSliceQuotient.AffineSlice data.1.2
((normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood).columns.map
(datumProjection S data)) (datumMatrix S data Nstar) =>
e.symm ⟨M.val, M.property.1.trans (datumMatrix_rows S data Nstar)⟩
have hlift (M) : datumMatrix S data (lift M) = M.val :=
congrArg Subtype.val (e.apply_symm_apply ⟨M.val, M.property.1.trans (datumMatrix_rows S data Nstar)⟩)
refine {
toFun := fun N => ⟨datumMatrix S data N.val, hrow N.val, ?_⟩
invFun := fun M => ⟨lift M, ?_⟩
left_inv := ?_
right_inv := ?_ }
· exact (ProjectedColumnSlice.contains_padded_iff D data.1.2
(normalizedDescription_spec S labeling α hα hsmall (datumLeft S data) hgood).1
(datumProjection S data) (datumMatrix S data Nstar) hs
(datumMatrix S data N.val) (hrow N.val)).mp
((slice_assemble_iff S labeling α hα hsmall data hgood N.val).mp N.property)
· apply (slice_assemble_iff S labeling α hα hsmall data hgood (lift M)).mpr
rw [hlift]
exact (ProjectedColumnSlice.contains_padded_iff D data.1.2
(normalizedDescription_spec S labeling α hα hsmall (datumLeft S data) hgood).1
(datumProjection S data) (datumMatrix S data Nstar) hs M.val M.property.1).mpr M.property.2
· intro N
apply Subtype.ext
exact e.symm_apply_apply N.val
· intro M
apply Subtype.ext
exact hlift M
@[simp] theorem selectedPrivateEquiv_val (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (hα : 0 < α) (hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(data : Datum S k s d r) (hgood : GoodAdvice S labeling α (datumLeft S data))
(Nstar : AdviceLaw.PrivateMap data)
(hstar : slice S k s d r labeling α (AdviceLaw.completeAssemble data Nstar) = true)
(N : {N : AdviceLaw.PrivateMap data //
slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true}) :
(selectedPrivateEquiv S labeling α hα hsmall data hgood Nstar hstar N).val =
datumMatrix S data N.val := rfl
/-- Exact conditional target probability, with no assumed uniformity premise. -/
theorem conditional_eq_transferred (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (hα : 0 < α) (hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(β : ℝ) (hβ : 0 ≤ β) (hβ' : β ≤ 1)
(data : Datum S k s d r) (hgood : GoodAdvice S labeling α (datumLeft S data))
(Nstar : AdviceLaw.PrivateMap data)
(hstar : slice S k s d r labeling α (AdviceLaw.completeAssemble data Nstar) = true)
(positive : 0 < (law S k s d r β hβ hβ').probability
(VisibleTransfer.fiberEvent AdviceLaw.completeObserve data (slice S k s d r labeling α))) :
((law S k s d r β hβ hβ').condition
(VisibleTransfer.fiberEvent AdviceLaw.completeObserve data (slice S k s d r labeling α))
positive).probability (targetHit S k s d r labeling α) =
SelectedDecoding.transferredAgreement S labeling (AdviceLaw.completeDraw data 0)
(normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood)
(normalizedDescription S labeling α hα hsmall (datumLeft S data) hgood).intercept
(datumMatrix S data Nstar) := by
let : Fintype (Fin S.occurrences) := Fin.fintype _
let : Fintype (Alphabet s) := @Pi.instFintype (Fin s) (fun _ => F2) (instDecidableEqFin s) (Fin.fintype s) (fun _ => ZMod.fintype 2)
let : Fintype (Vector d) := @Pi.instFintype (Fin d) (fun _ => F2) (instDecidableEqFin d) (Fin.fintype d) (fun _ => ZMod.fintype 2)
let : Fintype (Vector r) := @Pi.instFintype (Fin r) (fun _ => F2) (instDecidableEqFin r) (Fin.fintype r) (fun _ => ZMod.fintype 2)
let : Fintype (Alphabet s →ₗ[F2] Vector r) := ActualConditionalLaw.homFintype
unfold law at positive ⊢
have hconditional := ActualConditionalLaw.probability_condition_complete
(k := k) (Id := Fin S.occurrences) (K := Alphabet s) (W := Vector d) (R := Vector r)
(FiniteDistribution.uniform (ActualGame.Question S k))
(FiniteDistribution.uniform (Alphabet s →ₗ[F2] Vector r)) β hβ hβ' data
(slice S k s d r labeling α) (targetHit S k s d r labeling α) (by
convert positive using 1
simp only [FiniteDistribution.probability,
AdviceLaw.fullSeedLaw, FiniteDistribution.product, FiniteDistribution.uniform,
← Nat.card_eq_fintype_card]
apply Finset.sum_congr (univ_congr_inline_SelectedFiberLaw _ _)
intro x hx
rfl)
refine Eq.trans ?_ (hconditional.trans ?_)
· apply condition_prob_enumeration
intro x
simp only [AdviceLaw.fullSeedLaw, FiniteDistribution.product, FiniteDistribution.uniform,
← Nat.card_eq_fintype_card]
·
let : Fintype (RawPartnerTarget.RawPoint (PaddedLaw.choiceMask data.2.1) →ₗ[F2] Alphabet s) :=
homFintype
let : Fintype (RowErasureSliceQuotient.AffineSlice data.1.2
((normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood).columns.map
(datumProjection S data)) (datumMatrix S data Nstar)) :=
SelectedDecoding.affineSliceFintype _ _ _
let f : {N : AdviceLaw.PrivateMap data //
slice S k s d r labeling α (AdviceLaw.completeAssemble data N) = true} → ℝ :=
fun N => if targetHit S k s d r labeling α (AdviceLaw.completeAssemble data N.val) = true
then 1 else 0
let g : RowErasureSliceQuotient.AffineSlice data.1.2
((normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood).columns.map
(datumProjection S data)) (datumMatrix S data Nstar) → ℝ :=
fun M => if TableKeysRestoration.projectedAnswer S k s d labeling
(PaddedLaw.choiceMask data.2.1)
(RawPrivateTable.supported (PaddedLaw.choiceMask data.2.1) (ActualGame.names S)
data.1.1 (PaddedLaw.choiceSlots data.2.1)) (M.val.prod data.2.2.1) =
M.val (datumProjection S data
(normalizedResponse S labeling α hα hsmall (datumLeft S data) hgood).coefficient) +
(normalizedDescription S labeling α hα hsmall (datumLeft S data) hgood).intercept
then 1 else 0
have he : (𝔼 N, f N) = 𝔼 M, g M := by
refine Fintype.expect_equiv
(selectedPrivateEquiv S labeling α hα hsmall data hgood Nstar hstar) f g ?_
intro N
dsimp only [f, g]
simp only [selectedPrivateEquiv_val]
exact TransferredDecoding.indicator_congr _ _ _ _
(target_assemble_iff S labeling α hα hsmall data hgood N.val N.property)
calc
_ = 𝔼 N, f N := by
apply Finset.expect_congr (by ext N; simp only [Finset.mem_univ])
intro N _
exact TransferredDecoding.indicator_congr _ _ _ _ Iff.rfl
_ = 𝔼 M, g M := he
_ = _ := by
unfold SelectedDecoding.transferredAgreement
apply Finset.expect_congr (univ_congr_inline_SelectedFiberLaw _ _)
intro M _
exact TransferredDecoding.indicator_congr _ _ _ _ Iff.rfl
/-- Every complete visible datum selected by the actual witness event pays the
private-decoding success constant. Good advice and a nonempty transferred
slice follow from positivity and are not additional hypotheses. -/
theorem visibleWitness_decoding (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α : ℝ) (hα : 0 < α) (hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(β : ℝ) (hβ : 0 ≤ β) (hβ' : β ≤ 1) (data : Datum S k s d r)
(hvisible : VisibleTransfer.visibleWitness (law S k s d r β hβ hβ')
AdviceLaw.completeObserve (slice S k s d r labeling α)
(targetHit S k s d r labeling α) (α / 4) data = true) :
(α / 8) ^ 2 / (2 : ℝ) ^ (s * r) / (2 : ℝ) ^ r ≤
ActualConditionalLaw.datumAgreement S labeling (goodPredicate S labeling α hα hsmall) data := by
obtain ⟨positive, hagree⟩ := VisibleTransfer.visibleWitness_conditional
(law S k s d r β hβ hβ') AdviceLaw.completeObserve
(slice S k s d r labeling α) (targetHit S k s d r labeling α) (α / 4) data hvisible
obtain ⟨Nstar, hstar⟩ := exists_selected_private S labeling α β hβ hβ' data positive
have hgood := good_of_selected_private S labeling α data Nstar hstar
rw [conditional_eq_transferred S labeling α hα hsmall β hβ hβ' data hgood Nstar hstar positive] at hagree
apply SelectedDecoding.observedAgreement_lower S labeling α hα hsmall
(AdviceLaw.completeDraw data 0) hgood (datumMatrix S data Nstar) ?_ hagree
exact (datumMatrix_rows S data Nstar).trans (datumMatrix_rows S data 0).symm
end MaxCutGames.Decoder.SelectedFiberLaw
end
/-! The full selected-witness argument on the actual projected experiment.
The variation comparison precedes all conditioning. Its visible event then
pays the independent private decoder success on every selected datum. -/
namespace MaxCutGames.Decoder.ActualProjectedTransfer
open Integration.BinaryLinear Reduction ActualSource Foundations.Games
open scoped BigOperators Classical
noncomputable section
attribute [local instance] Classical.propDecidable
attribute [local instance] Fintype.ofFinite
local instance homFintype {D F : Type*}
[AddCommGroup D] [Module F2 D] [AddCommGroup F] [Module F2 F]
[Fintype D] [Fintype F] : Fintype (D →ₗ[F2] F) :=
Fintype.ofInjective (fun M : D →ₗ[F2] F => (M : D → F)) DFunLike.coe_injective
variable {k s d r : ℕ}
def slopeVariation (k s d : ℕ) (β : ℝ) : ℝ :=
Foundations.Information.totalVariation
(SparseLaw.independentWeights
(SparseLaw.mixture β (SparseLaw.singletonPairWeights (Ambient s d))) k)
(SparseLaw.uniformWeights (Fin k → Ambient s d × Ambient s d))
/-- The actual complete-data event has positive mass depending only on the
fixed inverse and alphabet parameters. -/
theorem visible_mass (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α g₀ β : ℝ) (hα : 0 < α) (hβ : 0 ≤ β) (hβ' : β ≤ 1)
(hgood : g₀ ≤ ActualGoodRows.adviceMass S k s d r labeling α)
(hvariation : slopeVariation k s d β ≤ ConstantSelection.variationBudget α g₀ s r) :
ConstantSelection.visibleMass α g₀ s r ≤
((ActualSeedEvents.law S k s d r β hβ hβ').pushforward AdviceLaw.completeObserve).probability
(VisibleTransfer.visibleWitness (ActualSeedEvents.law S k s d r β hβ hβ')
AdviceLaw.completeObserve (ActualSeedEvents.slice S k s d r labeling α)
(ActualSeedEvents.targetHit S k s d r labeling α) (α / 4)) := by
have htv := (ActualSeedVariation.actual_totalVariation_le_slope S k s d r β hβ hβ').trans hvariation
have h := VisibleTransfer.projected_witness_mass
(ActualEvents.unrestricted S k s d r) (ActualSeedEvents.law S k s d r β hβ hβ')
(ActualSeedEvents.pad S k s d r) AdviceLaw.completeObserve
(ActualEvents.sliceEvent S k s d r labeling α) (ActualEvents.targetHit S k s d r labeling α)
α g₀ (1 / (2 : ℝ) ^ (s * r)) hα.le
(ActualEvents.slice_probability_lower S k s d r labeling α g₀ hgood)
(ActualEvents.target_probability_lower S k s d r labeling α)
(ConstantSelection.variationBudget_suffices hα s r htv)
have hc : α * g₀ * (1 / (2 : ℝ) ^ (s * r)) / 8 =
ConstantSelection.visibleMass α g₀ s r := by
unfold ConstantSelection.visibleMass
ring
rw [hc] at h
exact h
/-- Integrating a pointwise lower bound over a genuine probability event. -/
theorem event_expectation_lower {Ω : Type*} [Fintype Ω]
(μ : FiniteDistribution Ω) (event : Ω → Bool) (f : Ω → ℝ)
(γ₁ γ₂ : ℝ) (hγ₂ : 0 ≤ γ₂) (hf : ∀ x, 0 ≤ f x)
(hmass : γ₁ ≤ μ.probability event)
(hpoint : ∀ x, event x = true → γ₂ ≤ f x) :
γ₁ * γ₂ ≤ μ.expectation f := by
have hweighted : μ.probability event * γ₂ ≤ μ.expectation f := by
unfold FiniteDistribution.probability FiniteDistribution.expectation
rw [Finset.sum_mul]
apply Finset.sum_le_sum
intro x _
by_cases hx : event x = true
· simp only [hx, ↓reduceIte]
exact mul_le_mul_of_nonneg_left (hpoint x hx) (μ.nonnegative x)
· simp only [hx, Bool.false_eq_true, ↓reduceIte, zero_mul]
exact mul_nonneg (μ.nonnegative x) (hf x)
exact (mul_le_mul_of_nonneg_right hmass hγ₂).trans hweighted
/-- End-to-end lower bound for actual local stochastic responses. No hidden
matrix, selected witness, or opposing observation is passed to a prover. -/
theorem actual_success_lower (S : Source)
(labeling : Fin (TableKeysGame.vertexCount S k s d) → Fin (2 ^ s))
(α g₀ β : ℝ) (hα : 0 < α)
(hsmall : 1 / (2 : ℝ) ^ (s - r) < α / 8)
(hβ : 0 ≤ β) (hβ' : β ≤ 1)
(hgood : g₀ ≤ ActualGoodRows.adviceMass S k s d r labeling α)
(hvariation : slopeVariation k s d β ≤ ConstantSelection.variationBudget α g₀ s r) :
ConstantSelection.decodingMass α g₀ s r ≤
(ActualSeedEvents.law S k s d r β hβ hβ').expectation
(fun seed => VisiblePolicies.observedAgreement S labeling
(SelectedPolicies.goodPredicate S labeling α hα hsmall)
(AdviceLaw.seedToActualDraw seed.1.1 seed.1.2 seed.2)) := by
let μ := ActualSeedEvents.law S k s d r β hβ hβ'
let good := SelectedPolicies.goodPredicate S labeling α hα hsmall
have h := event_expectation_lower (μ.pushforward AdviceLaw.completeObserve)
(VisibleTransfer.visibleWitness μ AdviceLaw.completeObserve
(ActualSeedEvents.slice S k s d r labeling α)
(ActualSeedEvents.targetHit S k s d r labeling α) (α / 4))
(ActualConditionalLaw.datumAgreement S labeling good)
(ConstantSelection.visibleMass α g₀ s r) (ConstantSelection.conditionalMass α s r)
(ConstantSelection.conditionalMass_pos hα s r).le
(ActualConditionalLaw.datumAgreement_nonneg S labeling good)
(visible_mass S labeling α g₀ β hα hβ hβ' hgood hvariation)
(SelectedFiberLaw.visibleWitness_decoding S labeling α hα hsmall β hβ hβ')
rw [FiniteDistribution.expectation_pushforward] at h
unfold ConstantSelection.decodingMass
convert h using 1
apply FiniteDistribution.expectation_congr
intro seed
exact ActualConditionalLaw.observedAgreement_seed S labeling good seed
end
end MaxCutGames.Decoder.ActualProjectedTransfer
end OAI