{"abstract":"Ascending coefficients are evaluated as descending coefficients.","category":"Polynomial arithmetic","checks":4,"contract":"Integer coefficients in ascending power order and integer evaluation bounds; missing high-degree coefficients are zero. Rational outputs are reduced Fraction strings; the zero-polynomial degree is -1. Ascending polynomial evaluation. Exact operational definition: sum(c*x**i for i,c in enumerate(coeff))","contract_signature":"coeff, x","evaluation_group":"model-2d5edcff4cde3f85","failed_approach":"Every coefficient is assigned the first power.","family":"xn-ascending-polynomial-evaluation","id":"FA-6101","implementations":{"attempt":{"sha256":"ea7a8a6c797dc15463fb94a45fbfdebe28441ad1ad1124378bd534a5bcc1c20c","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(coeff, x):\n    return sum(c*x for c in coeff)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([1, 2, 3], 2)', solve(*([1, 2, 3], 2)), 17)\ncheck('fixture 2: ([4], 7)', solve(*([4], 7)), 4)\ncheck('fixture 3: ([], 2)', solve(*([], 2)), 0)\ncheck('fixture 4: ([0, 1], -3)', solve(*([0, 1], -3)), -3)\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":"ffe4b919ff71730eb51f9e3938b6b84c8d2b1727eb24ee95305f6f192565265e","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(coeff, x):\n    return sum(c*x**i for i,c in enumerate(reversed(coeff)))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([1, 2, 3], 2)', solve(*([1, 2, 3], 2)), 17)\ncheck('fixture 2: ([4], 7)', solve(*([4], 7)), 4)\ncheck('fixture 3: ([], 2)', solve(*([], 2)), 0)\ncheck('fixture 4: ([0, 1], -3)', solve(*([0, 1], -3)), -3)\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-ascending-polynomial-evaluation","generated_at":"2026-09-29T14:37:57.676395+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. Polynomial arithmetic results depend on the stated convention.","root_cause":"Ascending coefficients are evaluated as descending coefficients.","sha256":"42cc08a43dfbbfe0e24161151a43dedb6b1bc48eb9811b908191aa1e46723001","title":"Ascending polynomial evaluation · 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":122.776,"exit_code":1,"observations":[{"actual":12,"check":"fixture 1: ([1, 2, 3], 2)","expected":17,"passed":false},{"actual":28,"check":"fixture 2: ([4], 7)","expected":4,"passed":false},{"actual":0,"check":"fixture 3: ([], 2)","expected":0,"passed":true},{"actual":-3,"check":"fixture 4: ([0, 1], -3)","expected":-3,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([1, 2, 3], 2)\", \"actual\": 12, \"expected\": 17, \"passed\": false}, {\"check\": \"fixture 2: ([4], 7)\", \"actual\": 28, \"expected\": 4, \"passed\": false}, {\"check\": \"fixture 3: ([], 2)\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4: ([0, 1], -3)\", \"actual\": -3, \"expected\": -3, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":46.037,"exit_code":1,"observations":[{"actual":11,"check":"fixture 1: ([1, 2, 3], 2)","expected":17,"passed":false},{"actual":4,"check":"fixture 2: ([4], 7)","expected":4,"passed":true},{"actual":0,"check":"fixture 3: ([], 2)","expected":0,"passed":true},{"actual":1,"check":"fixture 4: ([0, 1], -3)","expected":-3,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([1, 2, 3], 2)\", \"actual\": 11, \"expected\": 17, \"passed\": false}, {\"check\": \"fixture 2: ([4], 7)\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 3: ([], 2)\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4: ([0, 1], -3)\", \"actual\": 1, \"expected\": -3, \"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."}}