Hacker News AI · 2026/10/13 20:40:04
BB(10) 超越葛立恒数:机器验证的图灵机新纪录与 Coq 证明链
该项目发布了经过形式化验证的 Busy Beaver (BB) 新结果,其中 BB(8) 状态机的停机步数与输出值已精确计算并超越葛立恒数量级。核心突破在于利用 Coq 证明助手对图灵机行为进行无公理(No axioms)的全程验证,确保了数学结论的绝对严谨性。这为研究不可判定性与超大规模计算提供了可复现、可验证的基准数据。
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本文目录4 个章节
busy-beaver
Busy beaver results, with machine-checked proofs.
BB8/
1RB0RA_1LC1LF_1RD0LB_1RA1LE_1RZ0LC_1RG1LD_1LC0RH_1RG1LF, an 8-state, 2-symbol machine that halts
from the blank tape with exactly
sigma = 12 * (2 ↑^37 3) + 59
ones (Knuth up-arrows), hence after more than 2 ↑^37 3 steps. It runs the BB(7) champion's program (Kropitz 2025, analysed by Ligocki) with 36 digits instead of 12.
BB8/1RB0RA_1LC1LF_1RD0LB_1RA1LE_1RZ0LC_1RG1LD_1LC0RH_1RG1LF.txt: the analysis, in the notation of the wiki page of the BB(7) champion (configurations, low/mid/high level rules, bound), and a comparison with that champion.BB8/verify/: Coq proofs on top of busycoq (bd2e36f, Coq 8.20.1):halt : halts tm c0, the score lower bounds2↑^11 2↑^11 3 < Nand2↑^35 2↑^35 3 < N, and the exact scoreN = 12 * (2↑^37 3) + 58(N counts the ones before the final write; score = N + 1). No axioms. SeeBB8/verify/README.mdfor the compile commands.BB8/tools/ligocki_notation.py: an independent cell-by-cell simulator that extracts theB(a; b, ..., z)configurations and rules of both machines.
BB9/
1RB0RA_1LC1LF_1RD0LB_1RA1LE_1LI0LC_1RG1LD_0RH0RF_0RG0RE_0LH1RZ, a 9-state, 2-symbol machine that halts
from the blank tape with exactly
sigma = 3 * (2 ↑^(6T-33) 8) + (54 T + 26) / 5, T = 2 ↑^13 3
ones, hence more than 2 ↑^(2 ↑^13 3) 3 (a tower of 2 ↑^13 3 up-arrows; about f_ω(6 · 2 ↑^13 3) in the fast-growing hierarchy). It runs the BB(7) champion's program to the point where that champion halts, re-encodes the result as a fresh digit list with 12B−11 digits (2B+4 = 2 ↑^13 3), runs the champion's program on that list, and halts. It beats the 2024 BB(9) champion of Jacobzheng, whose exact score is computed in the same proof. A twin with H0 = 0RH has the same score.
BB9/1RB0RA_..._0LH1RZ.txt: the analysis (configurations, rules, the four phases of the run, the exact score, the hierarchy value, the comparison with the champion).BB9/verify/:BB9_record_1RB0RA_selfcontained.v, ONE Coq file depending only on the standard library (busycoqbd2e36finlined, Coq 8.20.1):halt, the exact score, the champion's halting and exact score, andnew_champion(score(champion) < score(ours), with a factor-3 margin). No axioms used. Check with plaincoqcin about an hour.verify/multifile/has the original development on busycoq, including the twin's proof.
BB10/
1RB0RA_1LC1LF_1RD0LB_1RA1LE_1LI0LC_0RG1LD_1RH1LG_1LC0RG_0LJ0LI_1RZ0LC (n1), a 10-state, 2-symbol machine
that halts from the blank tape with more than
G^N(33) ones, G(x) = 2 ↑^(x+1) 3, N = (6T − 19)/7, T = 2 ↑^37 3
(machine-checked). Also machine-checked, with the standard definitions of the fast-growing hierarchy and of Graham's number: f_(ω+1)((3T−13)/7 − 2) < sigma < f_(ω+1)(6T), so its level is exactly ω+1, and sigma > Graham's number. It runs a sibling of the BB(8) record to the point where that machine halts with the value T, turns T into a countdown of about 0.43 T periods, and in every period re-encodes its latest (astronomical) value as the length of the list it clears next, so that each period applies one f_ω-sized step; it halts when the countdown runs out (which happens because T ≡ 2 mod 7). It beats the BB(10) champion of Racheline (2024), against that champion's Coq-proved exact score. The exact score is also proved, as an explicit recursion of Knuth arrows.
BB10/1RB0RA_..._0LJ0LI_1RZ0LC.md: the analysis (overview, notation, rules, the full run, the exact score, size analysis, comparisons, verification status).BB10/verify/: Coq proofs on busycoq (bd2e36f, Coq 8.20.1):halt, the exact score (score_exact, closed formscore_closed_unfolded), the lower bound,beats_championagainst the champion's own exact score, the hierarchy levelfgh_levelandbeats_graham. No axioms.verify/multifile/compile_clean.shrebuilds everything and runs a probe that re-checks the transition table entry by entry.BB10/verify/BB10_n1_selfcontained.vis the same proof as one file that needs only the Coq standard library (coqc BB10_n1_selfcontained.v, about 13 minutes).BB10/tools/bb10_n1_writeup_chk.py: an independent literal simulator that re-checks every rule of the analysis on concrete instances.BB10/screen/: the heuristic candidate screen that found n1 (completion enumerator, mini-follower, the cleared-list filter), with its data and acheck.shthat reproduces part of it. Its verdicts are not claims.
BB12/
1RB0RA_1LC1LF_1RD0LB_1RA1LE_1LI0LC_0RG1LD_1RH1LG_1LC0RG_0LJ0LI_1RK0LC_0RL---_0RF1RZ (T12a), a 12-state, 2-symbol
machine that halts from the blank tape with N ones, where (machine-checked, standard fast-growing hierarchy)
f_(ω+1)(f_(ω+1)(JJ − 2)) ≤ 6N + 11, JJ = (3T − 13)/7, T = 2 ↑^37 3.
It is n1 (BB10/) with two more states. It runs n1's whole computation. Where n1 halts, it rebuilds a countdown in place from n1's final values, runs n1's period loop a second time (about f_ω(w) more f_ω-sized steps, where w is n1's final depth), and halts at the end of that second round. It beats n1, against n1's Coq-proved exact score. One transition (K1) is never read.
BB12/1RB0RA_..._0RL---_0RF1RZ.md: the analysis (how it works, the run, the score, comparisons, verification status).BB12/verify/: Coq proofs on busycoq (bd2e36f, Coq 8.20.1):halt, the lower boundssigma_lower_boundandscore_ge_exact,beats_n1, and the hierarchy boundfgh_lower2. No axioms.verify/multifile/compile_clean.shrebuilds everything (one 2.6 MB file takes most of the time) and runs a probe that re-checks the transition table entry by entry.
(注:更多技术实现细节与完整 API 文档请查阅原项目 README)