{"abstract":"Sign is tested before the sign line is uninverted.","category":"PCM sample encoding","checks":8,"contract":"Undo a per-line XOR inversion map within a signed PCM field before interpreting sign and detecting canonical zero.","contract_signature":"codes, width, xor_mask","evaluation_group":"s3-pcm-xor-coded-pcm","failed_approach":"Using the inversion mask as sample sign forces a constant polarity interpretation.","family":"s3-pcm-xor-coded-pcm-signed-field","id":"FA-49056","implementations":{"attempt":{"sha256":"fa3a0c82a75791366eeaf88fd11e471f553e8c85bffed1e0f5b8d17dfb7e09d8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(codes, width, xor_mask):\n    field=(1<<width)-1\n    out=[]\n    for raw in codes:\n        code=(raw^xor_mask)&field\n        sign=1<<(width-1)\n        value=code-(1<<width) if xor_mask&sign else code\n        out.append([value, code==0])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([0, 3, 7, 8, 15], 4, 5)), [[5, False], [6, False], [2, False], [-3, False], [-6, False]])\ncheck('oracle 2', solve(*([8, 0, 15], 4, 8)), [[0, True], [-8, False], [7, False]])\ncheck('oracle 3', solve(*([16, 31, 0], 4, 32)), [[0, True], [-1, False], [0, True]])\ncheck('oracle 4', solve(*([0, 255], 8, 85)), [[85, False], [-86, False]])\ncheck('oracle 5', solve(*([], 3, 7)), [])\ncheck('oracle 6', solve(*([0, 1], 1, 1)), [[-1, False], [0, True]])\ncheck('oracle 7', solve(*([3, 4, 7], 3, 2)), [[1, False], [-2, False], [-3, False]])\nif N == 1: check('variant packet 1', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 2: check('variant packet 2', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 3: check('variant packet 3', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 4: check('variant packet 4', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 5: check('variant packet 5', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\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":"3e732a6edc71f25b9b028f5fd63ea8b9e088efafa9415e768f29864eca6ab08f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(codes, width, xor_mask):\n    field=(1<<width)-1\n    out=[]\n    for raw in codes:\n        code=(raw^xor_mask)&field\n        sign=1<<(width-1)\n        value=code-(1<<width) if raw&sign else code\n        out.append([value, code==0])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([0, 3, 7, 8, 15], 4, 5)), [[5, False], [6, False], [2, False], [-3, False], [-6, False]])\ncheck('oracle 2', solve(*([8, 0, 15], 4, 8)), [[0, True], [-8, False], [7, False]])\ncheck('oracle 3', solve(*([16, 31, 0], 4, 32)), [[0, True], [-1, False], [0, True]])\ncheck('oracle 4', solve(*([0, 255], 8, 85)), [[85, False], [-86, False]])\ncheck('oracle 5', solve(*([], 3, 7)), [])\ncheck('oracle 6', solve(*([0, 1], 1, 1)), [[-1, False], [0, True]])\ncheck('oracle 7', solve(*([3, 4, 7], 3, 2)), [[1, False], [-2, False], [-3, False]])\nif N == 1: check('variant packet 1', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 2: check('variant packet 2', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 3: check('variant packet 3', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 4: check('variant packet 4', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\nif N == 5: check('variant packet 5', solve(*[[0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15, 0, 3, 7, 8, 15], 4, 5]), [[5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False], [5, False], [6, False], [2, False], [-3, False], [-6, False]])\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":"Stipulated finite model; no claim of hardware timing or full file-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-pcm-xor-coded-pcm-signed-field","generated_at":"2026-09-29T14:44:56.385097+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline PCM interchange uses these exact bounded packet and sample representation decisions.","root_cause":"Sign is tested before the sign line is uninverted.","sha256":"5cf2c9bfb771512a65aa6d9621d3178367e73f8a2e15f5e89b9912899afc0166","title":"Xor coded pcm: signed field · 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":41.427,"exit_code":1,"observations":[{"actual":[[5,false],[6,false],[2,false],[13,false],[10,false]],"check":"oracle 1","expected":[[5,false],[6,false],[2,false],[-3,false],[-6,false]],"passed":false},{"actual":[[-16,true],[-8,false],[-9,false]],"check":"oracle 2","expected":[[0,true],[-8,false],[7,false]],"passed":false},{"actual":[[0,true],[15,false],[0,true]],"check":"oracle 3","expected":[[0,true],[-1,false],[0,true]],"passed":false},{"actual":[[85,false],[170,false]],"check":"oracle 4","expected":[[85,false],[-86,false]],"passed":false},{"actual":[],"check":"oracle 5","expected":[],"passed":true},{"actual":[[-1,false],[-2,true]],"check":"oracle 6","expected":[[-1,false],[0,true]],"passed":false},{"actual":[[1,false],[6,false],[5,false]],"check":"oracle 7","expected":[[1,false],[-2,false],[-3,false]],"passed":false},{"actual":[[5,false],[6,false],[2,false],[13,false],[10,false],[5,false],[6,false],[2,false],[13,false],[10,false]],"check":"variant packet 1","expected":[[5,false],[6,false],[2,false],[-3,false],[-6,false],[5,false],[6,false],[2,false],[-3,false],[-6,false]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[5, false], [6, false], [2, false], [13, false], [10, false]], \"expected\": [[5, false], [6, false], [2, false], [-3, false], [-6, false]], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[-16, true], [-8, false], [-9, false]], \"expected\": [[0, true], [-8, false], [7, false]], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[0, true], [15, false], [0, true]], \"expected\": [[0, true], [-1, false], [0, true]], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[85, false], [170, false]], \"expected\": [[85, false], [-86, false]], \"passed\": false}, {\"check\": \"oracle 5\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[-1, false], [-2, true]], \"expected\": [[-1, false], [0, true]], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[1, false], [6, false], [5, false]], \"expected\": [[1, false], [-2, false], [-3, false]], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[5, false], [6, false], [2, false], [13, false], [10, false], [5, false], [6, false], [2, false], [13, false], [10, false]], \"expected\": [[5, false], [6, false], [2, false], [-3, false], [-6, false], [5, false], [6, false], [2, false], [-3, false], [-6, false]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.064,"exit_code":1,"observations":[{"actual":[[5,false],[6,false],[2,false],[-3,false],[-6,false]],"check":"oracle 1","expected":[[5,false],[6,false],[2,false],[-3,false],[-6,false]],"passed":true},{"actual":[[-16,true],[8,false],[-9,false]],"check":"oracle 2","expected":[[0,true],[-8,false],[7,false]],"passed":false},{"actual":[[0,true],[-1,false],[0,true]],"check":"oracle 3","expected":[[0,true],[-1,false],[0,true]],"passed":true},{"actual":[[85,false],[-86,false]],"check":"oracle 4","expected":[[85,false],[-86,false]],"passed":true},{"actual":[],"check":"oracle 5","expected":[],"passed":true},{"actual":[[1,false],[-2,true]],"check":"oracle 6","expected":[[-1,false],[0,true]],"passed":false},{"actual":[[1,false],[-2,false],[-3,false]],"check":"oracle 7","expected":[[1,false],[-2,false],[-3,false]],"passed":true},{"actual":[[5,false],[6,false],[2,false],[-3,false],[-6,false],[5,false],[6,false],[2,false],[-3,false],[-6,false]],"check":"variant packet 1","expected":[[5,false],[6,false],[2,false],[-3,false],[-6,false],[5,false],[6,false],[2,false],[-3,false],[-6,false]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[5, false], [6, false], [2, false], [-3, false], [-6, false]], \"expected\": [[5, false], [6, false], [2, false], [-3, false], [-6, false]], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [[-16, true], [8, false], [-9, false]], \"expected\": [[0, true], [-8, false], [7, false]], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[0, true], [-1, false], [0, true]], \"expected\": [[0, true], [-1, false], [0, true]], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[85, false], [-86, false]], \"expected\": [[85, false], [-86, false]], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[1, false], [-2, true]], \"expected\": [[-1, false], [0, true]], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[1, false], [-2, false], [-3, false]], \"expected\": [[1, false], [-2, false], [-3, false]], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[5, false], [6, false], [2, false], [-3, false], [-6, false], [5, false], [6, false], [2, false], [-3, false], [-6, false]], \"expected\": [[5, false], [6, false], [2, false], [-3, false], [-6, false], [5, false], [6, false], [2, false], [-3, false], [-6, false]], \"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."}}