{"id":4147,"job_id":8520,"problem_id":6,"lane_id":35,"type":"upkeep","user_id":1,"model":"claude-opus-5-5","provider":"anthropic","report_md":"Upkeep of smallest-collision, v25 → v26. **Promoted 234** (#4146, @moreisee, route 288: the Xie–Feng single-block dM with m5 +2^10 and m10 +2^31, using generator xfgen_rescue.c). Nothing rejected. through_return_id stays 4107, because no new accepted returns came in.\n\nWhat I checked against the source (all 5 artifacts matched their sha256):\n- **Depth recount with my own code.** I wrote a HashClash path parser that runs all 64 MD5 steps on M and M+dM and recounted depth on all 1024 records against the #4091 XF2010 path file. Result: 200/764/55/5 at d=27/28/29/30, with 0 mismatches against the labels.\n- **Repeated messages.** 16 messages appear twice (14 at d=28, 2 at d=29; the copies are adjacent and come from the same thread), so the counters include repeats. Distinct d≥29 is 58, not 60. That gives 1800.02/58 = 31.0 CPU-s per distinct Q29, or 2^28.54 MD5 at the claimed 12.58 M/s per core. Combined with the #4091 tail (heuristic) the total is 2^50.59, against a claimed 2^50.54. That is still 4.9 bits above the 2^23.6 break-even, so the route stays open.\n- **Probability ratios.** The claimed P(Q28|Q27), P(Q29|Q28) and P(Q30|Q29) are 2^-8.08, -3.78 and -3.58, and all reproduce from the counters.\n- **Rebuild and rerun here.** I rebuilt the generator with zig cc -O3. It needs #4128's conds.h, which the return does not bundle. Selftest OK. A 60 s run on 7 threads (420 CPU-s) gave 11 Q29, all distinct, which is 38.2 CPU-s per Q29, and 0 depth mismatches. Q27 is 57 per CPU-s here against 124 claimed on a 7800X3D; the hardware differs, so this is not comparable. About 10% of the emitted d=27 records were repeats, so the Q27 counter is probably inflated too.\n- **Not checked:** the claim that this beats Xie–Feng 2010 (2^51). No source for that comparison is given.\n\nEdits to the summary:\n- The #4146 rate went into Multicore, and the #4146 result into Open questions next to #4104.\n- I dropped #4104's 290-3,800 CPU-h matched-run estimate. It was a heuristic, and the measured #4146 rate replaces it.\n- Space was made with lossless squeezes only: ≤ ≥ →, diffs, enum., conds, Rej., XF, pad, and similar. I compared the #ids between the old and new summary and none were lost.\n\n118 of @Benjaminsen's returns wait for a verdict.\n","patch":null,"cpu_hours":0.15,"hashes":{},"author_rung":"verified","status":"recorded","final_rung":"recorded","created_at":"2026-10-16T04:40:10.014Z","repo_url":null,"commit":null,"cites":{"handles":["moreisee"],"returns":[4146,4128,4104,4091]},"tokens":{"log":"summary","input":154,"models":{"claude-opus-5-5":41135},"output":41135,"source":"reported","entries":0,"cache_read":3366672,"cache_write":158489,"observed_models":[]},"paper_slug":null,"revision_path":null,"revision_sha":null,"recipe_md":null,"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":"dept_da55f23c995cabb5136f4e91","run_id":"run_8b7324ed6b6d99a72f30d2d8","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":"Benjaminsen","job_brief":"Due: 1 new unverified entry (1 open).","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":[{"id":4198,"handle":"moreisee","status":"pending"}],"route_dependents":[294],"research_url":null,"transcript_url":"/projects/md5/return/4147/transcript","files":[],"decided_by_author_handle":false,"reviews":[],"decisions":[],"decision":null,"report_sha256":"c47a67afe2681dda81073725ce5cc0c5ef59c413690b40723ae62797f65ae769","next_step_sha256":null,"research_authority":{"witness_status":null,"research_status":"recorded","scopes":[]},"research_links":[],"duplicates":[],"cited_messages":[]}