{"abstract":"Two Heron factors are duplicated instead of respecting all three sides.","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. a,b,c satisfy the non-strict triangle inequality; return sixteen times triangle area squared. Exact operational definition: (a+b+c)*(-a+b+c)*(a-b+c)*(a+b-c)","contract_signature":"a, b, c","evaluation_group":"model-9891d83915f6657d","failed_approach":"One of the four factors is omitted.","family":"xn-squared-heron-area-times-sixteen","id":"FA-5886","implementations":{"attempt":{"sha256":"c3e2efe0d9bcd887e541e3920a9eab44afd1e5baf3ff97753f64b42238001370","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, c):\n    return (a+b+c)*(-a+b+c)*(a-b+c)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: (3, 4, 5)', solve(*(3, 4, 5)), 576)\ncheck('fixture 2: (2, 2, 2)', solve(*(2, 2, 2)), 48)\ncheck('fixture 3: (1, 2, 3)', solve(*(1, 2, 3)), 0)\ncheck('fixture 4: (5, 5, 6)', solve(*(5, 5, 6)), 2304)\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":"9876e2ad357537848ade22ce90ad19ac4a9aaeb8864945f3c0fdf4c75b5f662d","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, c):\n    return (a+b+c)*(a+b+c)*(a+b-c)*(a+b-c)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: (3, 4, 5)', solve(*(3, 4, 5)), 576)\ncheck('fixture 2: (2, 2, 2)', solve(*(2, 2, 2)), 48)\ncheck('fixture 3: (1, 2, 3)', solve(*(1, 2, 3)), 0)\ncheck('fixture 4: (5, 5, 6)', solve(*(5, 5, 6)), 2304)\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-squared-heron-area-times-sixteen","generated_at":"2026-09-29T14:37:54.933307+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":"Two Heron factors are duplicated instead of respecting all three sides.","sha256":"06ad253fea8056c63801f9ca42c110e63d5095d2d6be9d49c84275231255ab1c","title":"Squared heron area times sixteen · 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":42.689,"exit_code":1,"observations":[{"actual":288,"check":"fixture 1: (3, 4, 5)","expected":576,"passed":false},{"actual":24,"check":"fixture 2: (2, 2, 2)","expected":48,"passed":false},{"actual":48,"check":"fixture 3: (1, 2, 3)","expected":0,"passed":false},{"actual":576,"check":"fixture 4: (5, 5, 6)","expected":2304,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: (3, 4, 5)\", \"actual\": 288, \"expected\": 576, \"passed\": false}, {\"check\": \"fixture 2: (2, 2, 2)\", \"actual\": 24, \"expected\": 48, \"passed\": false}, {\"check\": \"fixture 3: (1, 2, 3)\", \"actual\": 48, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 4: (5, 5, 6)\", \"actual\": 576, \"expected\": 2304, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":136.943,"exit_code":1,"observations":[{"actual":576,"check":"fixture 1: (3, 4, 5)","expected":576,"passed":true},{"actual":144,"check":"fixture 2: (2, 2, 2)","expected":48,"passed":false},{"actual":0,"check":"fixture 3: (1, 2, 3)","expected":0,"passed":true},{"actual":4096,"check":"fixture 4: (5, 5, 6)","expected":2304,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: (3, 4, 5)\", \"actual\": 576, \"expected\": 576, \"passed\": true}, {\"check\": \"fixture 2: (2, 2, 2)\", \"actual\": 144, \"expected\": 48, \"passed\": false}, {\"check\": \"fixture 3: (1, 2, 3)\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4: (5, 5, 6)\", \"actual\": 4096, \"expected\": 2304, \"passed\": false}], \"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."}}