{"abstract":"Case folding leaves a decomposed identity.","category":"Unicode","checks":4,"contract":"Return NFC after case folding.","evaluation_group":"model-b001dd1566d13f3d","failed_approach":"The attempted repair handles the primary example but still violates a separate boundary of the same contract.","family":"xp-canonical-casefold-order","id":"FA-2856","implementations":{"attempt":{"sha256":"6b33d5236b48bcb3c497f5d52d5eb93b3ae9525ea8d1af70a390774374c9373a","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.casefold()\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('ǰ'), 'ǰ')\ncheck('boundary 2', solve('Å'), 'å')\ncheck('boundary 3', solve('Straße'), 'strasse')\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":"4e93288254cca956d7c05158939748fbb951ecfdb2950674fb66416ad86e48b2","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 unicodedata.normalize('NFC',x).casefold()\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('ǰ'), 'ǰ')\ncheck('boundary 2', solve('Å'), 'å')\ncheck('boundary 3', solve('Straße'), 'strasse')\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"},"fixed":{"sha256":"c4edf5ddb2a32915dbb93428866d73345e129ec9b49257bdc143b0ce225601a2","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 unicodedata.normalize('NFC',x.casefold())\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('ǰ'), 'ǰ')\ncheck('boundary 2', solve('Å'), 'å')\ncheck('boundary 3', solve('Straße'), 'strasse')\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-canonical-casefold-order","generated_at":"2026-09-29T14:37:18.020286+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: Return NFC after case folding.","root_cause":"The implementation applies an operation whose text or grammar semantics violate this contract: Return NFC after case folding.","sha256":"a05498a0d4bf6311a1c6e2258c34fb4263f917bc9b3282568a4fb00cf9da9739","title":"Case folding leaves a decomposed identity · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":106.241,"exit_code":1,"observations":[{"actual":"ǰ","check":"boundary 1","expected":"ǰ","passed":false},{"actual":"å","check":"boundary 2","expected":"å","passed":false},{"actual":"strasse","check":"boundary 3","expected":"strasse","passed":true},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"ǰ\", \"expected\": \"ǰ\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"å\", \"expected\": \"å\", \"passed\": false}, {\"check\": \"boundary 3\", \"actual\": \"strasse\", \"expected\": \"strasse\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":60.32,"exit_code":1,"observations":[{"actual":"ǰ","check":"boundary 1","expected":"ǰ","passed":false},{"actual":"å","check":"boundary 2","expected":"å","passed":true},{"actual":"strasse","check":"boundary 3","expected":"strasse","passed":true},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"ǰ\", \"expected\": \"ǰ\", \"passed\": false}, {\"check\": \"boundary 2\", \"actual\": \"å\", \"expected\": \"å\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"strasse\", \"expected\": \"strasse\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":49.028,"exit_code":0,"observations":[{"actual":"ǰ","check":"boundary 1","expected":"ǰ","passed":true},{"actual":"å","check":"boundary 2","expected":"å","passed":true},{"actual":"strasse","check":"boundary 3","expected":"strasse","passed":true},{"actual":"x","check":"boundary 4","expected":"x","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"boundary 1\", \"actual\": \"ǰ\", \"expected\": \"ǰ\", \"passed\": true}, {\"check\": \"boundary 2\", \"actual\": \"å\", \"expected\": \"å\", \"passed\": true}, {\"check\": \"boundary 3\", \"actual\": \"strasse\", \"expected\": \"strasse\", \"passed\": true}, {\"check\": \"boundary 4\", \"actual\": \"x\", \"expected\": \"x\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}