{"abstract":"A multiplication operator binds no tighter than addition.","category":"Parsing","checks":4,"contract":"Parse valid alternating operands and +/* into binary ASTs, with multiplication binding first and equal precedence associating left.","contract_signature":"x","evaluation_group":"model-a2f193620f91a67f","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-infix-multiplication-precedence","id":"FA-4066","implementations":{"attempt":{"sha256":"18ed7a64af872267b2a2aa812b4f37de28b477e179e27fea1bd8749556fece1c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        tree=x[-1]\n        for i in range(len(x)-2,0,-2): tree=[x[i],x[i-1],tree]\n        return tree\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve(['a', '+', 'b', '*', 'c']), ['+', 'a', ['*', 'b', 'c']])\ncheck('boundary 2', solve(['a', '*', 'b', '+', 'c']), ['+', ['*', 'a', 'b'], 'c'])\ncheck('boundary 3', solve(['a', '+', 'b', '+', 'c']), ['+', ['+', 'a', 'b'], 'c'])\ncheck('boundary 4', solve(['x']), 'x')\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":"b678a8332b81ac1883bb1352f3a25f839ea41b171b7669b3ef95341e30cedf14","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct\nfrom urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit\nfrom email.header import decode_header, make_header\nfrom email.utils import getaddresses\nfrom xml.etree import ElementTree as ET\nimport shlex, string, textwrap\n\nN = 1\nobservations = []\ndef solve(x):\n    try:\n        tree=x[0]\n        for i in range(1,len(x),2): tree=[x[i],tree,x[i+1]]\n        return tree\n    except Exception as exc:\n        return {\"error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('boundary 1', solve(['a', '+', 'b', '*', 'c']), ['+', 'a', ['*', 'b', 'c']])\ncheck('boundary 2', solve(['a', '*', 'b', '+', 'c']), ['+', ['*', 'a', 'b'], 'c'])\ncheck('boundary 3', solve(['a', '+', 'b', '+', 'c']), ['+', ['+', 'a', 'b'], 'c'])\ncheck('boundary 4', solve(['x']), 'x')\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":"xp-infix-multiplication-precedence","generated_at":"2026-09-29T14:37:35.173300+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Parse valid alternating operands and +/* into binary ASTs, with multiplication binding first and equal precedence associating left.","sha256":"44ab407500d8b7cbed8af474fcc1d60eb1a8e3876e677648a03b24ec4d0c212c","title":"A multiplication operator binds no tighter than addition · 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":52.368,"exit_code":1,"observations":[{"actual":["+","a",["*","b","c"]],"check":"boundary 1","expected":["+","a",["*","b","c"]],"passed":true},{"actual":["*","a",["+","b","c"]],"check":"boundary 2","expected":["+",["*","a","b"],"c"],"passed":false},{"actual":["+","a",["+","b","c"]],"check":"boundary 3","expected":["+",["+","a","b"],"c"],"passed":false},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"+\", \"a\", [\"*\", \"b\", \"c\"]], \"expected\": [\"+\", \"a\", [\"*\", \"b\", \"c\"]], \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": [\"*\", \"a\", [\"+\", \"b\", \"c\"]], \"expected\": [\"+\", [\"*\", \"a\", \"b\"], \"c\"], \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": [\"+\", \"a\", [\"+\", \"b\", \"c\"]], \"expected\": [\"+\", [\"+\", \"a\", \"b\"], \"c\"], \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":57.512,"exit_code":1,"observations":[{"actual":["*",["+","a","b"],"c"],"check":"boundary 1","expected":["+","a",["*","b","c"]],"passed":false},{"actual":["+",["*","a","b"],"c"],"check":"boundary 2","expected":["+",["*","a","b"],"c"],"passed":true},{"actual":["+",["+","a","b"],"c"],"check":"boundary 3","expected":["+",["+","a","b"],"c"],"passed":true},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": [\"*\", [\"+\", \"a\", \"b\"], \"c\"], \"expected\": [\"+\", \"a\", [\"*\", \"b\", \"c\"]], \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": [\"+\", [\"*\", \"a\", \"b\"], \"c\"], \"expected\": [\"+\", [\"*\", \"a\", \"b\"], \"c\"], \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": [\"+\", [\"+\", \"a\", \"b\"], \"c\"], \"expected\": [\"+\", [\"+\", \"a\", \"b\"], \"c\"], \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"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."}}