{"abstract":"Capitalization leaves an uppercase tail.","category":"Text processing","checks":4,"contract":"Capitalize the first character and lowercase the remainder using Unicode rules.","evaluation_group":"model-73dda9e734b76fd0","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-capitalize-lower-tail","id":"FA-2906","implementations":{"attempt":{"sha256":"6c2da461dc3a926aa6b5f1940dd400915729e0b8454e015e52ff95057db5e7a7","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        return x.title()\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('hELLO'), 'Hello')\ncheck('boundary 2', solve('two WORDS'), 'Two words')\ncheck('boundary 3', solve('dzABC'), 'Dzabc')\ncheck('boundary 4', solve(''), '')\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":"27a6e212dfa5a7b6668a36c437358f757e5c590a1b6e223148bba0e302c37b6d","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        return x[:1].upper()+x[1:]\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('hELLO'), 'Hello')\ncheck('boundary 2', solve('two WORDS'), 'Two words')\ncheck('boundary 3', solve('dzABC'), 'Dzabc')\ncheck('boundary 4', solve(''), '')\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":"df4aee8c140afabd53f0b827763ef49360ecc32fbbe7d85697be0a54570e4b70","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        return x.capitalize()\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('hELLO'), 'Hello')\ncheck('boundary 2', solve('two WORDS'), 'Two words')\ncheck('boundary 3', solve('dzABC'), 'Dzabc')\ncheck('boundary 4', solve(''), '')\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-capitalize-lower-tail","generated_at":"2026-09-29T14:37:18.805817+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.","repair":"Implement the complete stated contract, including the boundary fixtures: Capitalize the first character and lowercase the remainder using Unicode rules.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Capitalize the first character and lowercase the remainder using Unicode rules.","sha256":"31a4c1e7eb9a01138158006987d723302bd7b26cc7d1b40a68b419ba104bbe45","title":"Capitalization leaves an uppercase tail · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":56.112,"exit_code":1,"observations":[{"actual":"Hello","check":"boundary 1","expected":"Hello","passed":true},{"actual":"Two Words","check":"boundary 2","expected":"Two words","passed":false},{"actual":"Dzabc","check":"boundary 3","expected":"Dzabc","passed":true},{"actual":"","check":"boundary 4","expected":"","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"Hello\", \"expected\": \"Hello\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"Two Words\", \"expected\": \"Two words\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"Dzabc\", \"expected\": \"Dzabc\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":52.715,"exit_code":1,"observations":[{"actual":"HELLO","check":"boundary 1","expected":"Hello","passed":false},{"actual":"Two WORDS","check":"boundary 2","expected":"Two words","passed":false},{"actual":"DZABC","check":"boundary 3","expected":"Dzabc","passed":false},{"actual":"","check":"boundary 4","expected":"","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"HELLO\", \"expected\": \"Hello\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"Two WORDS\", \"expected\": \"Two words\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"DZABC\", \"expected\": \"Dzabc\", \"passed\": false}, {\"check\": \"boundary 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":54.775,"exit_code":0,"observations":[{"actual":"Hello","check":"boundary 1","expected":"Hello","passed":true},{"actual":"Two words","check":"boundary 2","expected":"Two words","passed":true},{"actual":"Dzabc","check":"boundary 3","expected":"Dzabc","passed":true},{"actual":"","check":"boundary 4","expected":"","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"Hello\", \"expected\": \"Hello\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"Two words\", \"expected\": \"Two words\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"Dzabc\", \"expected\": \"Dzabc\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}