{"abstract":"Storage length is mistaken for the highest nonzero degree.","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. Polynomial degree trailing zeroes. Exact operational definition: max((i for i,c in enumerate(coeff) if c),default=-1)","evaluation_group":"model-87572a66d2a67e1c","failed_approach":"The lowest nonzero degree is selected instead.","family":"xn-polynomial-degree-trailing-zeroes","id":"FA-6126","implementations":{"attempt":{"sha256":"e41c0b1cf3c94da911b074af494f6695214a96c6cae2d2f1055816773d2e0df9","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):\n    return next((i for i,c in enumerate(coeff) if c),-1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([1, 2, 0, 0],)', solve(*([1, 2, 0, 0],)), 1)\ncheck('fixture 2: ([0, 0],)', solve(*([0, 0],)), -1)\ncheck('fixture 3: ([],)', solve(*([],)), -1)\ncheck('fixture 4: ([0, 0, 3],)', solve(*([0, 0, 3],)), 2)\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":"fdef1b221457bf2a700ee2e444683b15c550c0e459212fc5f841bcbbc4ca69bd","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):\n    return len(coeff)-1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([1, 2, 0, 0],)', solve(*([1, 2, 0, 0],)), 1)\ncheck('fixture 2: ([0, 0],)', solve(*([0, 0],)), -1)\ncheck('fixture 3: ([],)', solve(*([],)), -1)\ncheck('fixture 4: ([0, 0, 3],)', solve(*([0, 0, 3],)), 2)\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"},"fixed":{"sha256":"ffecc320ffd2e70740b97ebeb270acf3e974e38fb9b340c0692271ab923a6e40","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):\n    return max((i for i,c in enumerate(coeff) if c),default=-1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([1, 2, 0, 0],)', solve(*([1, 2, 0, 0],)), 1)\ncheck('fixture 2: ([0, 0],)', solve(*([0, 0],)), -1)\ncheck('fixture 3: ([],)', solve(*([],)), -1)\ncheck('fixture 4: ([0, 0, 3],)', solve(*([0, 0, 3],)), 2)\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-polynomial-degree-trailing-zeroes","generated_at":"2026-09-29T14:37:57.852766+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.","repair":"Apply the specified mathematical contract directly, preserving all terms and boundary cases: return max((i for i,c in enumerate(coeff) if c),default=-1)","root_cause":"Storage length is mistaken for the highest nonzero degree.","sha256":"e8785acdf5467ede7fd995bb07b7a450c9627c05f749f89d0f66167d764af664","title":"Polynomial degree trailing zeroes · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":43.659,"exit_code":1,"observations":[{"actual":0,"check":"fixture 1: ([1, 2, 0, 0],)","expected":1,"passed":false},{"actual":-1,"check":"fixture 2: ([0, 0],)","expected":-1,"passed":true},{"actual":-1,"check":"fixture 3: ([],)","expected":-1,"passed":true},{"actual":2,"check":"fixture 4: ([0, 0, 3],)","expected":2,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([1, 2, 0, 0],)\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 2: ([0, 0],)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 3: ([],)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 4: ([0, 0, 3],)\", \"actual\": 2, \"expected\": 2, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.421,"exit_code":1,"observations":[{"actual":3,"check":"fixture 1: ([1, 2, 0, 0],)","expected":1,"passed":false},{"actual":1,"check":"fixture 2: ([0, 0],)","expected":-1,"passed":false},{"actual":-1,"check":"fixture 3: ([],)","expected":-1,"passed":true},{"actual":2,"check":"fixture 4: ([0, 0, 3],)","expected":2,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([1, 2, 0, 0],)\", \"actual\": 3, \"expected\": 1, \"passed\": false}, {\"check\": \"fixture 2: ([0, 0],)\", \"actual\": 1, \"expected\": -1, \"passed\": false}, {\"check\": \"fixture 3: ([],)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 4: ([0, 0, 3],)\", \"actual\": 2, \"expected\": 2, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":43.27,"exit_code":0,"observations":[{"actual":1,"check":"fixture 1: ([1, 2, 0, 0],)","expected":1,"passed":true},{"actual":-1,"check":"fixture 2: ([0, 0],)","expected":-1,"passed":true},{"actual":-1,"check":"fixture 3: ([],)","expected":-1,"passed":true},{"actual":2,"check":"fixture 4: ([0, 0, 3],)","expected":2,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([1, 2, 0, 0],)\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"fixture 2: ([0, 0],)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 3: ([],)\", \"actual\": -1, \"expected\": -1, \"passed\": true}, {\"check\": \"fixture 4: ([0, 0, 3],)\", \"actual\": 2, \"expected\": 2, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}