{"abstract":"Zero is assigned a positive direction.","category":"Integer arithmetic","checks":4,"contract":"Integer arguments; denominators, steps, moduli, and bit widths are positive. Unsigned word inputs fit the specified width except where masking is explicitly the operation. Sequence sizes are nonnegative. Integer signum. Exact operational definition: (n>0)-(n<0)","contract_signature":"n","evaluation_group":"model-2fa25c8f5e999d81","failed_approach":"Floating sign transfer also treats zero as positive.","family":"xn-integer-signum","id":"FA-5436","implementations":{"attempt":{"sha256":"65f4c2142169daca6042026386e17d62132153102ff861c6e7b2d7928db3f173","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nimport calendar\nimport statistics\nimport itertools\nfrom fractions import Fraction\nfrom datetime import date, datetime, timedelta, timezone\nfrom decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR\n\nN = 1\nobservations = []\ndef solve(n):\n    return int(math.copysign(1,n))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: (-5,)', solve(*(-5,)), -1)\ncheck('fixture 2: (0,)', solve(*(0,)), 0)\ncheck('fixture 3: (7,)', solve(*(7,)), 1)\ncheck('fixture 4: (1606938044258990275541962092341162602522202993782792835301376,)', solve(*(1606938044258990275541962092341162602522202993782792835301376,)), 1)\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":"2dc8ce3bfe48bb387218b01045092d875ee273e52820043694a40c4db0184064","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nimport calendar\nimport statistics\nimport itertools\nfrom fractions import Fraction\nfrom datetime import date, datetime, timedelta, timezone\nfrom decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR\n\nN = 1\nobservations = []\ndef solve(n):\n    return 1 if n>=0 else -1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: (-5,)', solve(*(-5,)), -1)\ncheck('fixture 2: (0,)', solve(*(0,)), 0)\ncheck('fixture 3: (7,)', solve(*(7,)), 1)\ncheck('fixture 4: (1606938044258990275541962092341162602522202993782792835301376,)', solve(*(1606938044258990275541962092341162602522202993782792835301376,)), 1)\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":" 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":"xn-integer-signum","generated_at":"2026-09-29T14:37:49.473567+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Small exact fixtures expose this error without platform timing, external services, or probabilistic observations. Integer mathematics results depend on the stated convention.","root_cause":"Zero is assigned a positive direction.","sha256":"61b257f81fcff37ba2d95c5dfc4d6f89002f5a059ddba3c61b457dd61022ad0e","title":"Integer signum · 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":43.325,"exit_code":1,"observations":[{"actual":-1,"check":"fixture 1: (-5,)","expected":-1,"passed":true},{"actual":1,"check":"fixture 2: (0,)","expected":0,"passed":false},{"actual":1,"check":"fixture 3: (7,)","expected":1,"passed":true},{"actual":1,"check":"fixture 4: (1606938044258990275541962092341162602522202993782792835301376,)","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: (-5,)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 2: (0,)\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3: (7,)\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 4: (1606938044258990275541962092341162602522202993782792835301376,)\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.434,"exit_code":1,"observations":[{"actual":-1,"check":"fixture 1: (-5,)","expected":-1,"passed":true},{"actual":1,"check":"fixture 2: (0,)","expected":0,"passed":false},{"actual":1,"check":"fixture 3: (7,)","expected":1,"passed":true},{"actual":1,"check":"fixture 4: (1606938044258990275541962092341162602522202993782792835301376,)","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: (-5,)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 2: (0,)\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3: (7,)\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 4: (1606938044258990275541962092341162602522202993782792835301376,)\", \"actual\": 1, \"expected\": 1, \"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."}}