{"abstract":"A structured table violates the declared record or column contract.","category":"Delimited text","checks":8,"contract":"Decode bitmap|comma-payload rows. Bitmap consists of 0 and 1; 1 denotes null and consumes no payload, 0 consumes one payload field. Empty payload encodes zero fields only when bitmap has no zero bits; otherwise it is one empty field. Reject leftover or insufficient values. Return logical cells.","evaluation_group":"s3-delimited-text-null-bitmap-row","failed_approach":"The alternate implementation still violates the same declared invariant: a null bitmap uses the opposite meaning for set bits.","family":"s3-delimited-text-null-bitmap-row-bit-polarity","id":"FA-48366","implementations":{"attempt":{"sha256":"d5d9fd86dc8f25b04a43df9ec986638f85886cc1465321026f9a047a799ab28b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    parts=data.split('|',1)\n    if len(parts)!=2: return None\n    bits,payload=parts\n    if any(bit not in '01' for bit in bits): return None\n    values=payload.split(',') if payload or '0' in bits else []\n    out=[]; cursor=0\n    for bit in bits:\n        if bit!='0': out.append('')\n        else:\n            if cursor>=len(values): return None\n            out.append(values[cursor]); cursor+=1\n    if cursor!=len(values): return None\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('mixed', solve(_vary('010|@,z')), _vary(['@', None, 'z']))\ncheck('all null', solve(_vary('111|')), _vary([None, None, None]))\ncheck('empty text', solve(_vary('0|')), _vary(['']))\ncheck('insufficient', solve(_vary('00|x')), _vary(None))\ncheck('extra', solve(_vary('1|x')), _vary(None))\ncheck('empty bitmap', solve(_vary('|')), _vary([]))\ncheck('invalid bit', solve(_vary('02|x,y')), _vary(None))\ncheck('several nulls', solve(_vary('1101|@')), _vary([None, None, '@', None]))\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":"37ba8ce0029d5161f5c515ead2b8602a5a81db3c9399a0dbb8120ef8be1123b0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    parts=data.split('|',1)\n    if len(parts)!=2: return None\n    bits,payload=parts\n    if any(bit not in '01' for bit in bits): return None\n    values=payload.split(',') if payload or '0' in bits else []\n    out=[]; cursor=0\n    for bit in bits:\n        if bit=='0': out.append(None)\n        else:\n            if cursor>=len(values): return None\n            out.append(values[cursor]); cursor+=1\n    if cursor!=len(values): return None\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('mixed', solve(_vary('010|@,z')), _vary(['@', None, 'z']))\ncheck('all null', solve(_vary('111|')), _vary([None, None, None]))\ncheck('empty text', solve(_vary('0|')), _vary(['']))\ncheck('insufficient', solve(_vary('00|x')), _vary(None))\ncheck('extra', solve(_vary('1|x')), _vary(None))\ncheck('empty bitmap', solve(_vary('|')), _vary([]))\ncheck('invalid bit', solve(_vary('02|x,y')), _vary(None))\ncheck('several nulls', solve(_vary('1101|@')), _vary([None, None, '@', None]))\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"},"fixed":{"sha256":"d3f8627ab8eb91edbe5738cecb9167d26b64fc4108ed0f83767ca3da0d215b85","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\ndef _vary(value):\n    if value == '@END': return 3 + 4*N\n    if isinstance(value, str): return value.replace('@', 'cell' * N)\n    if isinstance(value, list): return [_vary(x) for x in value]\n    if isinstance(value, dict): return {_vary(k): _vary(v) for k,v in value.items()}\n    return value\nN = 1\nobservations = []\ndef solve(data):\n    parts=data.split('|',1)\n    if len(parts)!=2: return None\n    bits,payload=parts\n    if any(bit not in '01' for bit in bits): return None\n    values=payload.split(',') if payload or '0' in bits else []\n    out=[]; cursor=0\n    for bit in bits:\n        if bit=='1': out.append(None)\n        else:\n            if cursor>=len(values): return None\n            out.append(values[cursor]); cursor+=1\n    if cursor!=len(values): return None\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('mixed', solve(_vary('010|@,z')), _vary(['@', None, 'z']))\ncheck('all null', solve(_vary('111|')), _vary([None, None, None]))\ncheck('empty text', solve(_vary('0|')), _vary(['']))\ncheck('insufficient', solve(_vary('00|x')), _vary(None))\ncheck('extra', solve(_vary('1|x')), _vary(None))\ncheck('empty bitmap', solve(_vary('|')), _vary([]))\ncheck('invalid bit', solve(_vary('02|x,y')), _vary(None))\ncheck('several nulls', solve(_vary('1101|@')), _vary([None, None, '@', None]))\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":"Deterministic bounded in-memory model. No claim of complete CSV or external format conformance. 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":"s3-delimited-text-null-bitmap-row-bit-polarity","generated_at":"2026-09-29T14:44:50.074024+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Delimited interchange needs explicit framing, schema and field semantics at ingestion and emission boundaries.","repair":"Preserve the named invariant at the faulty decision: if bit=='1': out.append(None)","root_cause":"A null bitmap uses the opposite meaning for set bits.","sha256":"299e0e65fb1b76acfd47eb549dad4359abf6af213fef0ac58b421b5dbda603b3","title":"A null bitmap uses the opposite meaning for set bits · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.364,"exit_code":1,"observations":[{"actual":["cell","","z"],"check":"mixed","expected":["cell",null,"z"],"passed":false},{"actual":["","",""],"check":"all null","expected":[null,null,null],"passed":false},{"actual":[""],"check":"empty text","expected":[""],"passed":true},{"actual":null,"check":"insufficient","expected":null,"passed":true},{"actual":null,"check":"extra","expected":null,"passed":true},{"actual":[],"check":"empty bitmap","expected":[],"passed":true},{"actual":null,"check":"invalid bit","expected":null,"passed":true},{"actual":["","","cell",""],"check":"several nulls","expected":[null,null,"cell",null],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"mixed\", \"actual\": [\"cell\", \"\", \"z\"], \"expected\": [\"cell\", null, \"z\"], \"passed\": false}, {\"check\": \"all null\", \"actual\": [\"\", \"\", \"\"], \"expected\": [null, null, null], \"passed\": false}, {\"check\": \"empty text\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}, {\"check\": \"insufficient\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"extra\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty bitmap\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"invalid bit\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"several nulls\", \"actual\": [\"\", \"\", \"cell\", \"\"], \"expected\": [null, null, \"cell\", null], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.625,"exit_code":1,"observations":[{"actual":null,"check":"mixed","expected":["cell",null,"z"],"passed":false},{"actual":null,"check":"all null","expected":[null,null,null],"passed":false},{"actual":null,"check":"empty text","expected":[""],"passed":false},{"actual":null,"check":"insufficient","expected":null,"passed":true},{"actual":["x"],"check":"extra","expected":null,"passed":false},{"actual":[],"check":"empty bitmap","expected":[],"passed":true},{"actual":null,"check":"invalid bit","expected":null,"passed":true},{"actual":null,"check":"several nulls","expected":[null,null,"cell",null],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"mixed\", \"actual\": null, \"expected\": [\"cell\", null, \"z\"], \"passed\": false}, {\"check\": \"all null\", \"actual\": null, \"expected\": [null, null, null], \"passed\": false}, {\"check\": \"empty text\", \"actual\": null, \"expected\": [\"\"], \"passed\": false}, {\"check\": \"insufficient\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"extra\", \"actual\": [\"x\"], \"expected\": null, \"passed\": false}, {\"check\": \"empty bitmap\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"invalid bit\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"several nulls\", \"actual\": null, \"expected\": [null, null, \"cell\", null], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.026,"exit_code":0,"observations":[{"actual":["cell",null,"z"],"check":"mixed","expected":["cell",null,"z"],"passed":true},{"actual":[null,null,null],"check":"all null","expected":[null,null,null],"passed":true},{"actual":[""],"check":"empty text","expected":[""],"passed":true},{"actual":null,"check":"insufficient","expected":null,"passed":true},{"actual":null,"check":"extra","expected":null,"passed":true},{"actual":[],"check":"empty bitmap","expected":[],"passed":true},{"actual":null,"check":"invalid bit","expected":null,"passed":true},{"actual":[null,null,"cell",null],"check":"several nulls","expected":[null,null,"cell",null],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"mixed\", \"actual\": [\"cell\", null, \"z\"], \"expected\": [\"cell\", null, \"z\"], \"passed\": true}, {\"check\": \"all null\", \"actual\": [null, null, null], \"expected\": [null, null, null], \"passed\": true}, {\"check\": \"empty text\", \"actual\": [\"\"], \"expected\": [\"\"], \"passed\": true}, {\"check\": \"insufficient\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"extra\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"empty bitmap\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"invalid bit\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"several nulls\", \"actual\": [null, null, \"cell\", null], \"expected\": [null, null, \"cell\", null], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}