Documentation

Complexitylib.Algebraic.LowerBound.Cutwidth.Extractor.Strong.Block.Recursion.Scheduled.Matched.Growing

Actual matched extraction at growing recursion depth #

An explicit arithmetic budget lets the existing matched Boolean program use arbitrary recursion depths. The complete retained seed still has 2^24 * L bits, the output has 2^h * L bits, and the error is 2^(-e). The input source entropy need only be 2^(2*h+14) * L bits. As with the fixed-depth theorem, an actual normalized source must fit that entropy threshold; the numerical guard alone does not assert source capacity.

These conservative finite deductions support the alternating widths in Chattopadhyay--Liao, Extractors for Sum of Two Sources, Theorem 6.1, https://arxiv.org/pdf/2110.12652. They use the scheduled extractor already constructed by the library and do not assert a complete affine correlation breaker or change the existing fixed-depth runtime guard.

theorem Algebraic.Cutwidth.Extractor.matchedBlockExtractor_growing_seedBits_le (n h L e : ℕ) (length : Nat.clog 2 (n + 1) ≤ L) (error : e + h + 2 ≤ L) (budget : (h + 1) * (e + 2 * h + Nat.clog 2 (L + 1) + 4) ≤ L) :

Paying the depth-error-logarithm product fits the actual seed in the fixed padded width.

theorem Algebraic.Cutwidth.Extractor.recursiveBlockEntropy_growing_le (h L e : ℕ) (positive : 1 ≤ L) (error : e + h + 2 ≤ L) :
recursiveBlockEntropy h (recursiveBlockReserve L (e + h + 2)) 0 ≤ 2 ^ (2 * h + 14) * L

The entropy exponent is quadratic in the power-of-two output factor.

theorem Algebraic.Cutwidth.Extractor.matchedBlockExtractor_growing_weighted (n h L e : ℕ) (length : Nat.clog 2 (n + 1) ≤ L) (error : e + h + 2 ≤ L) (budget : (h + 1) * (e + 2 * h + Nat.clog 2 (L + 1) + 4) ≤ L) :

The exact scheduled entropy threshold works for every depth satisfying the seed budget.

theorem Algebraic.Cutwidth.Extractor.matchedBlockExtractor_growing (n h L e : ℕ) (length : Nat.clog 2 (n + 1) ≤ L) (error : e + h + 2 ≤ L) (budget : (h + 1) * (e + 2 * h + Nat.clog 2 (L + 1) + 4) ≤ L) :
WeightedStrongSeededExtractor (matchedBlockExtractor n h L e) (2 ^ (2 ^ (2 * h + 14) * L)) (2 ^ e)⁻¹

A simple entropy reserve gives the same actual program's strong guarantee at any depth.

Logarithmic depth supplies the middle extractor's reserve and all prefix/output leakage.