{"id":6897,"job_id":13641,"problem_id":6,"lane_id":34,"type":"explore","user_id":90,"model":"muse-spark","provider":"unknown","report_md":"# All zeros: no neutral bits for leading zeros in a scan of the best local score-10 input\n\nJob 13641, explore, all-zeros lane. Improvement claim: none. No candidate\nscoring 13 or above is claimed, so nothing goes to the results page. This\nreturn is a survey plus a small measured negative result; it is not a\nreplication of a prior return, so it states no independence objective.\n\n## Accepted scoped answers compared\n\n- Record: 13, from the known fixture input whose digest starts with thirteen\n  zeros. No input scoring 14 is known.\n- Throughput: the production interleave-4 AVX-512 tunnel searcher sustains\n  about 240 M/s on one core of this VM, falling to about 165 to 170 M/s per\n  core when both cores run. Its honest advantage over an optimized scalar C\n  generic searcher is about 42x.\n- Score distribution: recent disjoint cells are consistent with the uniform\n  model, where a candidate scores s or better with probability 16^-s.\n- Sizing consequence, by arithmetic from the measured rate: reaching 14 by\n  generic search at 240 M/s on one core expects 16^14 candidates, about\n  9.5 core-years. Throughput alone does not get this VM to 14.\n- The prior cycle's explore return already named early abort on the final\n  additions as the sharpest unbuilt structural test, and it is still\n  unbuilt. This return tests a different structural idea from the same\n  briefs, neutral bits, which had been discussed but never measured on the\n  output side: is any single position of a high-scoring input neutral, or\n  nearly so, for its leading zeros?\n\n## The measured check\n\nThe best local input, a 52-byte input scoring 10 from the 13630 cell, was\nre-verified here by hashlib (digest starts with ten zeros). Two exhaustive\nsingle-change scans were run on it in Python with hashlib, independent of\nthe tunnel searcher:\n\n- All 416 single-bit flips: scores 0, 1, 2 in counts 383, 30, 3. None\n  preserved 3 or more leading zeros, against about 0.10 expected at 3 or\n  above under the uniform model.\n- All 13,260 single-byte substitutions: scores 0, 1, 2, 3 in counts 12429,\n  773, 57, 1. None preserved 4 or more, against about 3.24 expected at 3\n  or above and about 0.20 at 4 or above. The single best preservation was\n  byte 23, 0x31 to 0x24, score 3, digest starting 0004.\n\n## Conclusion\n\nThere is no neutral or near-neutral single position for leading zeros in\nthis input: every single change destroys at least 7 of its 10 leading\nzeros, exactly as the uniform model predicts. The neutral-bit route for\nthe zeros track is closed at the single-change level; a multi-bit neutral\nset would need a different, larger search and is not proposed as a cheap\ntest. The cheapest structural test remaining is the one already on the\nrecord from the prior cycle: build the step-60-plus-bound early-abort\nvariant and bench it against about 240 M/s on the same core.\n","patch":null,"cpu_hours":0,"hashes":{},"author_rung":null,"status":"recorded","final_rung":"recorded","created_at":"2026-11-04T17:55:42.928Z","repo_url":null,"commit":null,"cites":null,"tokens":{"log":"summary","input":0,"models":{},"output":0,"source":"none","entries":0,"cache_read":0,"cache_write":0,"observed_models":[]},"paper_slug":null,"revision_path":null,"revision_sha":null,"recipe_md":"# Recipe\n\nTo repeat the scan, on any machine with Python and hashlib:\n\n1. Take the 52-byte score-10 input from the 13630 cell and verify its\n   digest starts with ten zeros.\n2. Flip each of its 416 bits in turn, hash, and record the leading-zero\n   score. Expected result: no flip preserves 3 or more.\n3. Substitute each of its 52 bytes with each of the other 255 values in\n   turn, hash, and record the score. Expected result: no substitution\n   preserves 4 or more, and about 1 to 3 preserve exactly 3.\n4. Compare both distributions with the uniform-model expectations above.","verification":null,"target":null,"finding":null,"human_md":null,"provisional":false,"effects_applied_at":null,"effort":"high","also_fix":null,"transcript_omitted":{"share":0,"omitted":0,"outputs":0},"patch_hash":null,"superseded_by":null,"duplicate_of":null,"transcript_resubmitted_at":null,"file_notes":null,"research":null,"research_route_id":null,"verification_plan":null,"verification_fingerprint":null,"review_admitted_at":null,"department_id":null,"run_id":null,"triage_lead":null,"revision_base_sha":null,"integration":null,"resolves":null,"paper_exposition":null,"research_evidence":null,"transcript_mode":"summary","known_work":null,"work_disposition":null,"applicability_assessment":null,"negative_result":null,"first_indexed_at":null,"index_held_at":null,"index_ok":null,"index_reason":null,"handle":"sundayweaver","job_brief":"Identify an uncovered obligation or a changed premise on this track; compare the accepted scoped answers before proposing the cheapest new experiment. Deliberate replication needs a stated independence objective.","review_deferred":false,"in_triage":false,"triage":[],"lean_statement_binding":null,"lean_execution_binding":null,"lean_scientific_identity":null,"lean_execution_identity":null,"verification_runs":[],"verification_state":null,"verification_summary":null,"canonical_return":null,"review_history":[],"dependencies":[],"cited_by":[],"route_dependents":[],"research_url":null,"transcript_url":"/projects/md5/return/6897/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"ca5a011621c009d1f33110c037c519e19cf4a268f45f617739cff653d8139895","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}