{"abstract":"K-mer windows span independent sequence records.","category":"Biological sequence representation","checks":6,"contract":"Return all length-k windows in record order, then position order, independently per record; k is positive and records contain ACGT only.","contract_signature":"records,k","evaluation_group":"model-66c6011797dacb7a","failed_approach":"Adding an N separator leaks artificial separator windows.","family":"z-bio_sequences-record-kmers","id":"FA-12506","implementations":{"attempt":{"sha256":"b364c3f5e71ca0cf2904616a6faed0d5f1ccaee7a90064d569a45dbafdc38022","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(records,k):\n    s='N'.join(records)\n    return [s[i:i+k] for i in range(len(s)-k+1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('variable records', solve(['A'*N,'C'],2), ['AA']*max(0,N-1))\ncheck('empty collection', solve([],2), [])\ncheck('short records', solve(['A','T'],2), [])\ncheck('exact', solve(['AC','GT'],2), ['AC','GT'])\ncheck('unit', solve(['A','','C'],1), ['A','C'])\ncheck('overlap', solve(['ACG'],2), ['AC','CG'])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"8070ee98295dc60a2912a4f614c1e2cfe125211170efaa561323f35aac23b53c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(records,k):\n    s=''.join(records)\n    return [s[i:i+k] for i in range(len(s)-k+1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('variable records', solve(['A'*N,'C'],2), ['AA']*max(0,N-1))\ncheck('empty collection', solve([],2), [])\ncheck('short records', solve(['A','T'],2), [])\ncheck('exact', solve(['AC','GT'],2), ['AC','GT'])\ncheck('unit', solve(['A','','C'],1), ['A','C'])\ncheck('overlap', solve(['ACG'],2), ['AC','CG'])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Synthetic strings and explicit policies only; no biological interpretation or laboratory workflow. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"z-bio_sequences-record-kmers","generated_at":"2026-09-29T14:38:57.488793+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"An offline abstract sequence-data model; useful for testing representation invariants without biological inference.","root_cause":"Concatenation creates windows across record boundaries.","sha256":"6d457e663808713987d75835f6eaf762f2a70402e280bb6fdf68d09bd258129f","title":"K-mer windows span independent sequence records · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.698,"exit_code":1,"observations":[{"actual":["AN","NC"],"check":"variable records","expected":[],"passed":false},{"actual":[],"check":"empty collection","expected":[],"passed":true},{"actual":["AN","NT"],"check":"short records","expected":[],"passed":false},{"actual":["AC","CN","NG","GT"],"check":"exact","expected":["AC","GT"],"passed":false},{"actual":["A","N","N","C"],"check":"unit","expected":["A","C"],"passed":false},{"actual":["AC","CG"],"check":"overlap","expected":["AC","CG"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"variable records\", \"actual\": [\"AN\", \"NC\"], \"expected\": [], \"passed\": false}, {\"check\": \"empty collection\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"short records\", \"actual\": [\"AN\", \"NT\"], \"expected\": [], \"passed\": false}, {\"check\": \"exact\", \"actual\": [\"AC\", \"CN\", \"NG\", \"GT\"], \"expected\": [\"AC\", \"GT\"], \"passed\": false}, {\"check\": \"unit\", \"actual\": [\"A\", \"N\", \"N\", \"C\"], \"expected\": [\"A\", \"C\"], \"passed\": false}, {\"check\": \"overlap\", \"actual\": [\"AC\", \"CG\"], \"expected\": [\"AC\", \"CG\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":43.362,"exit_code":1,"observations":[{"actual":["AC"],"check":"variable records","expected":[],"passed":false},{"actual":[],"check":"empty collection","expected":[],"passed":true},{"actual":["AT"],"check":"short records","expected":[],"passed":false},{"actual":["AC","CG","GT"],"check":"exact","expected":["AC","GT"],"passed":false},{"actual":["A","C"],"check":"unit","expected":["A","C"],"passed":true},{"actual":["AC","CG"],"check":"overlap","expected":["AC","CG"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"variable records\", \"actual\": [\"AC\"], \"expected\": [], \"passed\": false}, {\"check\": \"empty collection\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"short records\", \"actual\": [\"AT\"], \"expected\": [], \"passed\": false}, {\"check\": \"exact\", \"actual\": [\"AC\", \"CG\", \"GT\"], \"expected\": [\"AC\", \"GT\"], \"passed\": false}, {\"check\": \"unit\", \"actual\": [\"A\", \"C\"], \"expected\": [\"A\", \"C\"], \"passed\": true}, {\"check\": \"overlap\", \"actual\": [\"AC\", \"CG\"], \"expected\": [\"AC\", \"CG\"], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}