{"abstract":"Reflection is performed about the origin rather than the specified line.","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. Reflection across horizontal line. Exact operational definition: (point[0],2*y-point[1])","contract_signature":"point, y","evaluation_group":"model-59911e2c2542f220","failed_approach":"The line offset is applied once rather than twice.","family":"xn-reflection-across-horizontal-line","id":"FA-5856","implementations":{"attempt":{"sha256":"9718c392321d0bb46b4444be44a683cd038f35e41a518a4dcd0cb34f8c6e123f","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(point, y):\n    return (point[0],y-point[1])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ((2, 3), 1)', solve(*((2, 3), 1)), (2, -1))\ncheck('fixture 2: ((0, 0), 2)', solve(*((0, 0), 2)), (0, 4))\ncheck('fixture 3: ((1, 4), 4)', solve(*((1, 4), 4)), (1, 4))\ncheck('fixture 4: ((-2, -3), -1)', solve(*((-2, -3), -1)), (-2, 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":"4cb5b64a019147a2767dc4e845fdd365567ca3da54b238cb056c50e674b989d1","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(point, y):\n    return (point[0],-point[1])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ((2, 3), 1)', solve(*((2, 3), 1)), (2, -1))\ncheck('fixture 2: ((0, 0), 2)', solve(*((0, 0), 2)), (0, 4))\ncheck('fixture 3: ((1, 4), 4)', solve(*((1, 4), 4)), (1, 4))\ncheck('fixture 4: ((-2, -3), -1)', solve(*((-2, -3), -1)), (-2, 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-reflection-across-horizontal-line","generated_at":"2026-09-29T14:37:54.482645+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":"Reflection is performed about the origin rather than the specified line.","sha256":"8c1b0c8e992376909531a49af56a658131cbb782a1a55c89e5360ad5b946c693","title":"Reflection across horizontal line · 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":50.955,"exit_code":1,"observations":[{"actual":[2,-2],"check":"fixture 1: ((2, 3), 1)","expected":[2,-1],"passed":false},{"actual":[0,2],"check":"fixture 2: ((0, 0), 2)","expected":[0,4],"passed":false},{"actual":[1,0],"check":"fixture 3: ((1, 4), 4)","expected":[1,4],"passed":false},{"actual":[-2,2],"check":"fixture 4: ((-2, -3), -1)","expected":[-2,1],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ((2, 3), 1)\", \"actual\": [2, -2], \"expected\": [2, -1], \"passed\": false}, {\"check\": \"fixture 2: ((0, 0), 2)\", \"actual\": [0, 2], \"expected\": [0, 4], \"passed\": false}, {\"check\": \"fixture 3: ((1, 4), 4)\", \"actual\": [1, 0], \"expected\": [1, 4], \"passed\": false}, {\"check\": \"fixture 4: ((-2, -3), -1)\", \"actual\": [-2, 2], \"expected\": [-2, 1], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":50.658,"exit_code":1,"observations":[{"actual":[2,-3],"check":"fixture 1: ((2, 3), 1)","expected":[2,-1],"passed":false},{"actual":[0,0],"check":"fixture 2: ((0, 0), 2)","expected":[0,4],"passed":false},{"actual":[1,-4],"check":"fixture 3: ((1, 4), 4)","expected":[1,4],"passed":false},{"actual":[-2,3],"check":"fixture 4: ((-2, -3), -1)","expected":[-2,1],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ((2, 3), 1)\", \"actual\": [2, -3], \"expected\": [2, -1], \"passed\": false}, {\"check\": \"fixture 2: ((0, 0), 2)\", \"actual\": [0, 0], \"expected\": [0, 4], \"passed\": false}, {\"check\": \"fixture 3: ((1, 4), 4)\", \"actual\": [1, -4], \"expected\": [1, 4], \"passed\": false}, {\"check\": \"fixture 4: ((-2, -3), -1)\", \"actual\": [-2, 3], \"expected\": [-2, 1], \"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."}}