{"abstract":"Separated axis extents are multiplied as negative lengths.","category":"Planar geometry","checks":4,"contract":"Integer coordinates and lengths, with exact arithmetic except for indicated division results. Lengths are nonnegative. Rectangles are (xmin,ymin,xmax,ymax) with ordered bounds; coordinate vectors have matching dimensions. Rectangle intersection area. Exact operational definition: max(0,min(a[2],b[2])-max(a[0],b[0]))*max(0,min(a[3],b[3])-max(a[1],b[1]))","contract_signature":"a, b","evaluation_group":"model-a26ec8ef8169c95e","failed_approach":"Clamping after multiplication admits two negative extents.","family":"xn-rectangle-intersection-area","id":"FA-5771","implementations":{"attempt":{"sha256":"8ec29d227e1a0ffe902786d07b547d691b66a7009307378ae514f80837679f97","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(a, b):\n    return max(0,(min(a[2],b[2])-max(a[0],b[0]))*(min(a[3],b[3])-max(a[1],b[1])))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ((0, 0, 2, 2), (1, 1, 3, 3))', solve(*((0, 0, 2, 2), (1, 1, 3, 3))), 1)\ncheck('fixture 2: ((0, 0, 1, 1), (2, 2, 3, 3))', solve(*((0, 0, 1, 1), (2, 2, 3, 3))), 0)\ncheck('fixture 3: ((0, 0, 1, 1), (2, 0, 3, 1))', solve(*((0, 0, 1, 1), (2, 0, 3, 1))), 0)\ncheck('fixture 4: ((0, 0, 2, 2), (2, 0, 4, 2))', solve(*((0, 0, 2, 2), (2, 0, 4, 2))), 0)\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":"fb9189754b1b5963d70bfb3e24fba7182684e858798aaf9c4089a8b660e12f04","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(a, b):\n    return (min(a[2],b[2])-max(a[0],b[0]))*(min(a[3],b[3])-max(a[1],b[1]))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ((0, 0, 2, 2), (1, 1, 3, 3))', solve(*((0, 0, 2, 2), (1, 1, 3, 3))), 1)\ncheck('fixture 2: ((0, 0, 1, 1), (2, 2, 3, 3))', solve(*((0, 0, 1, 1), (2, 2, 3, 3))), 0)\ncheck('fixture 3: ((0, 0, 1, 1), (2, 0, 3, 1))', solve(*((0, 0, 1, 1), (2, 0, 3, 1))), 0)\ncheck('fixture 4: ((0, 0, 2, 2), (2, 0, 4, 2))', solve(*((0, 0, 2, 2), (2, 0, 4, 2))), 0)\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-rectangle-intersection-area","generated_at":"2026-09-29T14:37:53.470831+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. Planar geometry results depend on the stated convention.","root_cause":"Separated axis extents are multiplied as negative lengths.","sha256":"eb59d07fe0942365bdd74dfc1331447bbaa3955d9ea23c5d22d4a594e64e25e3","title":"Rectangle intersection area · 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":48.982,"exit_code":1,"observations":[{"actual":1,"check":"fixture 1: ((0, 0, 2, 2), (1, 1, 3, 3))","expected":1,"passed":true},{"actual":1,"check":"fixture 2: ((0, 0, 1, 1), (2, 2, 3, 3))","expected":0,"passed":false},{"actual":0,"check":"fixture 3: ((0, 0, 1, 1), (2, 0, 3, 1))","expected":0,"passed":true},{"actual":0,"check":"fixture 4: ((0, 0, 2, 2), (2, 0, 4, 2))","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ((0, 0, 2, 2), (1, 1, 3, 3))\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 2: ((0, 0, 1, 1), (2, 2, 3, 3))\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3: ((0, 0, 1, 1), (2, 0, 3, 1))\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4: ((0, 0, 2, 2), (2, 0, 4, 2))\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.336,"exit_code":1,"observations":[{"actual":1,"check":"fixture 1: ((0, 0, 2, 2), (1, 1, 3, 3))","expected":1,"passed":true},{"actual":1,"check":"fixture 2: ((0, 0, 1, 1), (2, 2, 3, 3))","expected":0,"passed":false},{"actual":-1,"check":"fixture 3: ((0, 0, 1, 1), (2, 0, 3, 1))","expected":0,"passed":false},{"actual":0,"check":"fixture 4: ((0, 0, 2, 2), (2, 0, 4, 2))","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ((0, 0, 2, 2), (1, 1, 3, 3))\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 2: ((0, 0, 1, 1), (2, 2, 3, 3))\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3: ((0, 0, 1, 1), (2, 0, 3, 1))\", \"actual\": -1, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 4: ((0, 0, 2, 2), (2, 0, 4, 2))\", \"actual\": 0, \"expected\": 0, \"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."}}