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Complexitylib.Metacomplexity.NisanWigderson.Reconstruction.GlobalSampling

Globally sampling NW reconstruction coordinates and advice #

This layer represents Hirahara's random coordinate, outside seed, later tail, and candidate bit by one fixed-width finite trial. Uniform restriction ensures that conditioning on any coordinate gives exactly the corresponding uniform reconstruction-advice distribution.

theorem Complexity.NWDesign.goodRawAdviceProbability_eq {outputLength inputLength seedLength : } (design : NWDesign outputLength inputLength seedLength) (hardFunction : (Fin inputLengthBool)Bool) (test : Finset (Fin outputLengthBool)) (current : Fin outputLength) (agreementThreshold : ) :
uniformProbability {raw : RawReconstructionAdvice outputLength seedLength | agreementThreshold design.reconstructionAgreementProbability hardFunction test current (design.reconstructionAdviceOfRaw current raw)} = design.goodReconstructionAdviceProbability hardFunction test current agreementThreshold

For a fixed coordinate, restricting uniform fixed-width raw advice gives exactly the canonical uniform reconstruction-advice probability.

theorem Complexity.NWDesign.goodReconstructionTrialProbability_eq_average {outputLength inputLength seedLength : } (design : NWDesign outputLength inputLength seedLength) (hardFunction : (Fin inputLengthBool)Bool) (test : Finset (Fin outputLengthBool)) (agreementThreshold : ) (houtputLength : 0 < outputLength) :
design.goodReconstructionTrialProbability hardFunction test agreementThreshold = (∑ current : Fin outputLength, design.goodReconstructionAdviceProbability hardFunction test current agreementThreshold) / outputLength

A global fixed-width trial chooses the hybrid coordinate uniformly and then realizes that coordinate's uniform reconstruction-advice distribution.

theorem Complexity.NWDesign.exists_orientation_sum_averageReconstructionAgreement_ge {outputLength inputLength seedLength : } (design : NWDesign outputLength inputLength seedLength) (hardFunction : (Fin inputLengthBool)Bool) (test : Finset (Fin outputLengthBool)) (advantage : ) (hadvantage : advantage (design.generator hardFunction).distinguishingAdvantage test) :
∃ (complement : Bool), outputLength / 2 + advantage current : Fin outputLength, design.averageReconstructionAgreement hardFunction (BitGenerator.orientTest test complement) current

The total oriented distinguishing advantage lower-bounds the sum of the coordinate-wise average reconstruction agreements above the half baseline.

theorem Complexity.NWDesign.exists_orientation_goodReconstructionTrialProbability_ge {outputLength inputLength seedLength : } (design : NWDesign outputLength inputLength seedLength) (hardFunction : (Fin inputLengthBool)Bool) (test : Finset (Fin outputLengthBool)) (density : ) (houtputLength : 0 < outputLength) (hdensity : 0 density) (hdensityLeOne : density 1) (hadvantage : density (design.generator hardFunction).distinguishingAdvantage test) :
∃ (complement : Bool), density / outputLength / 2 design.goodReconstructionTrialProbability hardFunction (BitGenerator.orientTest test complement) (1 / 2 + density / outputLength / 2)

Hirahara's one-tuple Markov bound: sampling the coordinate together with fixed-width raw advice produces a predictor with half the average advantage with probability at least half the average advantage.

theorem Complexity.NWDesign.repeatedGoodReconstructionTrialProbability_eq_one_sub_pow {outputLength inputLength seedLength : } (design : NWDesign outputLength inputLength seedLength) (hardFunction : (Fin inputLengthBool)Bool) (test : Finset (Fin outputLengthBool)) (agreementThreshold : ) (trials : ) (houtputLength : 0 < outputLength) :
design.repeatedGoodReconstructionTrialProbability hardFunction test agreementThreshold trials = 1 - (1 - design.goodReconstructionTrialProbability hardFunction test agreementThreshold) ^ trials

Exact independent-repetition law for globally sampled reconstruction coordinates and raw advice.

theorem Complexity.NWDesign.exists_goodReconstructionTrialProbability_ge_of_randomTest {outputLength inputLength seedLength tapes time threshold budget : } {design : NWDesign outputLength inputLength seedLength} {hardFunction : (Fin inputLengthBool)Bool} {machine : TM tapes} {test : Finset (Fin outputLengthBool)} {density : } (houtputLength : 0 < outputLength) (hdensity : 0 density) (hlow : (design.generator hardFunction).HasLowTimeBoundedComplexity machine time threshold) (hrandom : BitGenerator.IsTimeBoundedRandomTest test machine time threshold) (hdense : BitGenerator.IsDenseTest test density) (hbudget : design.HasOverlapBudget budget) :
∃ (complement : Bool), density / outputLength / 2 design.goodReconstructionTrialProbability hardFunction (BitGenerator.orientTest test complement) (1 / 2 + density / outputLength / 2) ∀ (trial : ReconstructionTrial outputLength seedLength), design.reconstructionDataBitsAt trial.1 budget + (seedLength - inputLength) + 1

A dense random test yields one test orientation for which a single global trial succeeds with probability at least δ/(2m); every trial coordinate has the same weak-design payload bound.

theorem Complexity.NWDesign.exists_half_le_canonicalRepeatedGoodTrial_of_randomTest {outputLength inputLength seedLength tapes time threshold budget : } {design : NWDesign outputLength inputLength seedLength} {hardFunction : (Fin inputLengthBool)Bool} {machine : TM tapes} {test : Finset (Fin outputLengthBool)} {density : } (houtputLength : 0 < outputLength) (hdensity : 0 < density) (hlow : (design.generator hardFunction).HasLowTimeBoundedComplexity machine time threshold) (hrandom : BitGenerator.IsTimeBoundedRandomTest test machine time threshold) (hdense : BitGenerator.IsDenseTest test density) (hbudget : design.HasOverlapBudget budget) :
∃ (complement : Bool), 1 / 2 design.repeatedGoodReconstructionTrialProbability hardFunction (BitGenerator.orientTest test complement) (1 / 2 + density / outputLength / 2) (reconstructionAdviceTrialCount outputLength density) ∀ (trial : ReconstructionTrial outputLength seedLength), design.reconstructionDataBitsAt trial.1 budget + (seedLength - inputLength) + 1

Fully global O(m/δ) advice search: ceil(2m/δ) independent fixed-width trials, each sampling its own coordinate and raw advice, find a predictor of agreement 1/2 + δ/(2m) with probability at least one half.

theorem Complexity.NWDesign.exists_half_le_canonicalRepeatedGoodTrial_of_seedDescriptions {outputLength inputLength seedLength tapes time threshold budget : } {design : NWDesign outputLength inputLength seedLength} {hardFunction : (Fin inputLengthBool)Bool} {machine : TM tapes} {test : Finset (Fin outputLengthBool)} {density : } (houtputLength : 0 < outputLength) (hdensity : 0 < density) (hseedLength : seedLength < threshold) (hproduces : ∀ (seed : Fin seedLengthBool), machine.ProducesInTime (List.ofFn seed) (List.ofFn (design.generator hardFunction seed)) time) (hrandom : BitGenerator.IsTimeBoundedRandomTest test machine time threshold) (hdense : BitGenerator.IsDenseTest test density) (hbudget : design.HasOverlapBudget budget) :
∃ (complement : Bool), 1 / 2 design.repeatedGoodReconstructionTrialProbability hardFunction (BitGenerator.orientTest test complement) (1 / 2 + density / outputLength / 2) (reconstructionAdviceTrialCount outputLength density) ∀ (trial : ReconstructionTrial outputLength seedLength), design.reconstructionDataBitsAt trial.1 budget + (seedLength - inputLength) + 1

The fully global canonical-count search with generator complexity discharged by direct short-seed descriptions.