{"abstract":"Summing coordinates uses the Manhattan norm.","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. Chebyshev point distance. Exact operational definition: max(abs(x-y) for x,y in zip(a,b))","contract_signature":"a, b","evaluation_group":"model-403468e7a550c6eb","failed_approach":"Signed coordinate differences can conceal the largest magnitude.","family":"xn-chebyshev-point-distance","id":"FA-5791","implementations":{"attempt":{"sha256":"41eaada27705c07e99401ccd6245ae659c42ef7e681ed50c3d78854f50cacbc3","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(x-y for x,y in zip(a,b))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ((0, 0), (3, 4))', solve(*((0, 0), (3, 4))), 4)\ncheck('fixture 2: ((0, 0), (1, -1))', solve(*((0, 0), (1, -1))), 1)\ncheck('fixture 3: ((2, 2), (2, 2))', solve(*((2, 2), (2, 2))), 0)\ncheck('fixture 4: ((-2, 0), (2, 0))', solve(*((-2, 0), (2, 0))), 4)\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":"65e00c328891cbb2f5d5f98f8476d2d0aa887183f1f69307675481fde727fda0","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 sum(abs(x-y) for x,y in zip(a,b))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ((0, 0), (3, 4))', solve(*((0, 0), (3, 4))), 4)\ncheck('fixture 2: ((0, 0), (1, -1))', solve(*((0, 0), (1, -1))), 1)\ncheck('fixture 3: ((2, 2), (2, 2))', solve(*((2, 2), (2, 2))), 0)\ncheck('fixture 4: ((-2, 0), (2, 0))', solve(*((-2, 0), (2, 0))), 4)\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-chebyshev-point-distance","generated_at":"2026-09-29T14:37:53.644278+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":"Summing coordinates uses the Manhattan norm.","sha256":"f2a9658bfebcb02d0bcd30aba37633ab628b5b3bb314187c2274d877ea593bd5","title":"Chebyshev point distance · 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":114.272,"exit_code":1,"observations":[{"actual":-3,"check":"fixture 1: ((0, 0), (3, 4))","expected":4,"passed":false},{"actual":1,"check":"fixture 2: ((0, 0), (1, -1))","expected":1,"passed":true},{"actual":0,"check":"fixture 3: ((2, 2), (2, 2))","expected":0,"passed":true},{"actual":0,"check":"fixture 4: ((-2, 0), (2, 0))","expected":4,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ((0, 0), (3, 4))\", \"actual\": -3, \"expected\": 4, \"passed\": false}, {\"check\": \"fixture 2: ((0, 0), (1, -1))\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 3: ((2, 2), (2, 2))\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4: ((-2, 0), (2, 0))\", \"actual\": 0, \"expected\": 4, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.992,"exit_code":1,"observations":[{"actual":7,"check":"fixture 1: ((0, 0), (3, 4))","expected":4,"passed":false},{"actual":2,"check":"fixture 2: ((0, 0), (1, -1))","expected":1,"passed":false},{"actual":0,"check":"fixture 3: ((2, 2), (2, 2))","expected":0,"passed":true},{"actual":4,"check":"fixture 4: ((-2, 0), (2, 0))","expected":4,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ((0, 0), (3, 4))\", \"actual\": 7, \"expected\": 4, \"passed\": false}, {\"check\": \"fixture 2: ((0, 0), (1, -1))\", \"actual\": 2, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 3: ((2, 2), (2, 2))\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4: ((-2, 0), (2, 0))\", \"actual\": 4, \"expected\": 4, \"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."}}