Tooling: 44× faster production verify_factor via packed-row equality with identical receipts

[VictorLiwentao]

Change and scope

At base 0fdd7d82de03e43c9e5a1000dfbcd380d1b687d2, scripts/experiments/complex_centers.py:verify_factor still used the historical nested entrywise loop over all scatter/gather pairs. Ross Richardson’s opt-in adapter research/central-factor-packed/ already proved an injective packed-row algorithm with identical receipts. This PR wires that equivalent check into the production source used by scripts/audit_complex_centers.py / make verify-certificates.

Only the source pin for scripts/experiments/complex_centers.py changes inside certificates/dyadic-central-factor.json. Every coefficient is still checked; factor generators, side/phase obligations and the retained historical 2^-31 language are unchanged.

Tooling improvement; no new kappa. Selected frontier untouched.

Result

On Linux / CPython 3.12.3 (Linux-6.12.94+-x86_64-with-glibc2.39), five alternating fresh-process pairs gave median wall time:

• factor-only: 2.615 → 0.059 seconds (44.06×)
• complete audit: 5.784 → 3.356 seconds (1.72×)

Timing is host-descriptive and is not a correctness gate. Every verify_factor receipt matches the baseline checker fieldwise.

Package: research/central-factor-production/.

Validation

python3.12 -I -B research/central-factor-production/verify.py
python3.12 -I -O -B research/central-factor-production/verify.py
python3.12 -B scripts/research_package.py --package research/central-factor-production
python3.12 -I -B research/central-factor-production/benchmark.py --rounds 5

Expected:

PASS_CENTRAL_FACTOR_PRODUCTION heights=[8, 10, 12, 18, 26] ... no_new_kappa
PASS_REGISTERED_RESEARCH_PACKAGE research/central-factor-production outcome=completed
PASS_IDENTICAL_CENTRAL_FACTOR_PRODUCTION_RECEIPTS

Default verify is read-only. Coefficient-mismatch and temp-copy corruption controls reject; require gates remain under -O. Full make verify, selected cold replay, Lean, and multiplication-theorem obligations were not rerun for this isolated historical-checker change.

Overlap and credit

Closest priors (different delivery): Ross Richardson’s research/central-factor-packed/ (opt-in packed adapter; this is the production wiring), CrocSwap/integer-mult-bounds#756, CrocSwap/integer-mult-bounds#2117 (same dyadic-central-factor.json, different pin key disjoint_tensor.py). No competing open PR on production verify_factor at refresh.

Douglas R. Colkitt authored the dyadic central factor and original checker. Ross Richardson authored the packed algorithm. Prepared by Wentao Li (VictorLiwentao, @Is__Victor) with substantial AI assistance, under Apache-2.0.