{"abstract":"Vector CASE evaluates ELSE errors on THEN-selected lanes.","category":"Data systems","checks":8,"contract":"Evaluate CASE over [condition,then-value,then-error,else-value,else-error] rows. Only True chooses THEN; False and None choose ELSE. Unchosen errors are not evaluated. Chosen errors become ERROR:<label>; a chosen null value remains None. Return one result per input lane.","contract_signature":"d","evaluation_group":"s3-data-systems-masked-case-evaluation","failed_approach":"Falling back to the unchosen error still makes a safe THEN fail.","family":"s3-data-systems-masked-case-evaluation-eager-else","id":"FA-45336","implementations":{"attempt":{"sha256":"9a40efdeb065f3ff2a7e6cad5f6dd00101ce863f9f580d6ef49c455e7fedba64","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        out=[]\n        for cond,tvalue,terror,fvalue,ferror in d:\n            choose=cond is True\n            if choose:\n                error=terror or ferror; value=tvalue\n            else:\n                error=ferror; value=fvalue\n            out.append('ERROR:'+error if error is not None else value)\n        return out\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('skip erroneous then', solve([[False, 1, 'T', 2, None]]), [2])\n    check('unknown skips then', solve([[None, 1, 'T', 2, None]]), [2])\n    check('skip erroneous else', solve([[True, 1, None, 2, 'F']]), [1])\n    check('chosen then error', solve([[True, 1, 'T', 2, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 1, None, 2, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 1, None]]), [None])\n    check('else null', solve([[False, 1, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 2:\n    check('skip erroneous then', solve([[False, 2, 'T', 3, None]]), [3])\n    check('unknown skips then', solve([[None, 2, 'T', 3, None]]), [3])\n    check('skip erroneous else', solve([[True, 2, None, 3, 'F']]), [2])\n    check('chosen then error', solve([[True, 2, 'T', 3, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 2, None, 3, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 2, None]]), [None])\n    check('else null', solve([[False, 2, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 3:\n    check('skip erroneous then', solve([[False, 3, 'T', 4, None]]), [4])\n    check('unknown skips then', solve([[None, 3, 'T', 4, None]]), [4])\n    check('skip erroneous else', solve([[True, 3, None, 4, 'F']]), [3])\n    check('chosen then error', solve([[True, 3, 'T', 4, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 3, None, 4, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 3, None]]), [None])\n    check('else null', solve([[False, 3, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 4:\n    check('skip erroneous then', solve([[False, 4, 'T', 5, None]]), [5])\n    check('unknown skips then', solve([[None, 4, 'T', 5, None]]), [5])\n    check('skip erroneous else', solve([[True, 4, None, 5, 'F']]), [4])\n    check('chosen then error', solve([[True, 4, 'T', 5, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 4, None, 5, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 4, None]]), [None])\n    check('else null', solve([[False, 4, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 5:\n    check('skip erroneous then', solve([[False, 5, 'T', 6, None]]), [6])\n    check('unknown skips then', solve([[None, 5, 'T', 6, None]]), [6])\n    check('skip erroneous else', solve([[True, 5, None, 6, 'F']]), [5])\n    check('chosen then error', solve([[True, 5, 'T', 6, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 5, None, 6, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 5, None]]), [None])\n    check('else null', solve([[False, 5, None, None, None]]), [None])\n    check('empty vector', 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":"a7973fca092a0d3a61e1b41a63cb527482e255756343455742f5dcf69aea6016","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        out=[]\n        for cond,tvalue,terror,fvalue,ferror in d:\n            choose=cond is True\n            if choose:\n                error=ferror if ferror is not None else terror; value=tvalue\n            else:\n                error=ferror; value=fvalue\n            out.append('ERROR:'+error if error is not None else value)\n        return out\n    except (IndexError, KeyError, ValueError, StopIteration) as exc:\n        return {\"representation_error\": type(exc).__name__}\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nif N == 1:\n    check('skip erroneous then', solve([[False, 1, 'T', 2, None]]), [2])\n    check('unknown skips then', solve([[None, 1, 'T', 2, None]]), [2])\n    check('skip erroneous else', solve([[True, 1, None, 2, 'F']]), [1])\n    check('chosen then error', solve([[True, 1, 'T', 2, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 1, None, 2, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 1, None]]), [None])\n    check('else null', solve([[False, 1, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 2:\n    check('skip erroneous then', solve([[False, 2, 'T', 3, None]]), [3])\n    check('unknown skips then', solve([[None, 2, 'T', 3, None]]), [3])\n    check('skip erroneous else', solve([[True, 2, None, 3, 'F']]), [2])\n    check('chosen then error', solve([[True, 2, 'T', 3, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 2, None, 3, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 2, None]]), [None])\n    check('else null', solve([[False, 2, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 3:\n    check('skip erroneous then', solve([[False, 3, 'T', 4, None]]), [4])\n    check('unknown skips then', solve([[None, 3, 'T', 4, None]]), [4])\n    check('skip erroneous else', solve([[True, 3, None, 4, 'F']]), [3])\n    check('chosen then error', solve([[True, 3, 'T', 4, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 3, None, 4, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 3, None]]), [None])\n    check('else null', solve([[False, 3, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 4:\n    check('skip erroneous then', solve([[False, 4, 'T', 5, None]]), [5])\n    check('unknown skips then', solve([[None, 4, 'T', 5, None]]), [5])\n    check('skip erroneous else', solve([[True, 4, None, 5, 'F']]), [4])\n    check('chosen then error', solve([[True, 4, 'T', 5, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 4, None, 5, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 4, None]]), [None])\n    check('else null', solve([[False, 4, None, None, None]]), [None])\n    check('empty vector', solve([]), [])\nelif N == 5:\n    check('skip erroneous then', solve([[False, 5, 'T', 6, None]]), [6])\n    check('unknown skips then', solve([[None, 5, 'T', 6, None]]), [6])\n    check('skip erroneous else', solve([[True, 5, None, 6, 'F']]), [5])\n    check('chosen then error', solve([[True, 5, 'T', 6, None]]), ['ERROR:T'])\n    check('chosen else error', solve([[False, 5, None, 6, 'F']]), ['ERROR:F'])\n    check('then null', solve([[True, None, None, 5, None]]), [None])\n    check('else null', solve([[False, 5, None, None, None]]), [None])\n    check('empty vector', 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":"Offline stipulated semantics over valid small inputs; no performance, concurrency, or production-engine conformance claim. 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":"s3-data-systems-masked-case-evaluation-eager-else","generated_at":"2026-09-29T14:44:21.458068+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A bounded deterministic data engine model makes representation and changelog faults reproducible.","root_cause":"masked-case-evaluation: Vector CASE evaluates ELSE errors on THEN-selected lanes.","sha256":"005680d31ceac0da1efaaa2c043845544fa397273434f0ae798a2af67730d6fc","title":"Vector CASE evaluates ELSE errors on THEN-selected lanes · 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":46.535,"exit_code":1,"observations":[{"actual":[2],"check":"skip erroneous then","expected":[2],"passed":true},{"actual":[2],"check":"unknown skips then","expected":[2],"passed":true},{"actual":["ERROR:F"],"check":"skip erroneous else","expected":[1],"passed":false},{"actual":["ERROR:T"],"check":"chosen then error","expected":["ERROR:T"],"passed":true},{"actual":["ERROR:F"],"check":"chosen else error","expected":["ERROR:F"],"passed":true},{"actual":[null],"check":"then null","expected":[null],"passed":true},{"actual":[null],"check":"else null","expected":[null],"passed":true},{"actual":[],"check":"empty vector","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"skip erroneous then\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"unknown skips then\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"skip erroneous else\", \"actual\": [\"ERROR:F\"], \"expected\": [1], \"passed\": false}, {\"check\": \"chosen then error\", \"actual\": [\"ERROR:T\"], \"expected\": [\"ERROR:T\"], \"passed\": true}, {\"check\": \"chosen else error\", \"actual\": [\"ERROR:F\"], \"expected\": [\"ERROR:F\"], \"passed\": true}, {\"check\": \"then null\", \"actual\": [null], \"expected\": [null], \"passed\": true}, {\"check\": \"else null\", \"actual\": [null], \"expected\": [null], \"passed\": true}, {\"check\": \"empty vector\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":46.122,"exit_code":1,"observations":[{"actual":[2],"check":"skip erroneous then","expected":[2],"passed":true},{"actual":[2],"check":"unknown skips then","expected":[2],"passed":true},{"actual":["ERROR:F"],"check":"skip erroneous else","expected":[1],"passed":false},{"actual":["ERROR:T"],"check":"chosen then error","expected":["ERROR:T"],"passed":true},{"actual":["ERROR:F"],"check":"chosen else error","expected":["ERROR:F"],"passed":true},{"actual":[null],"check":"then null","expected":[null],"passed":true},{"actual":[null],"check":"else null","expected":[null],"passed":true},{"actual":[],"check":"empty vector","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"skip erroneous then\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"unknown skips then\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"skip erroneous else\", \"actual\": [\"ERROR:F\"], \"expected\": [1], \"passed\": false}, {\"check\": \"chosen then error\", \"actual\": [\"ERROR:T\"], \"expected\": [\"ERROR:T\"], \"passed\": true}, {\"check\": \"chosen else error\", \"actual\": [\"ERROR:F\"], \"expected\": [\"ERROR:F\"], \"passed\": true}, {\"check\": \"then null\", \"actual\": [null], \"expected\": [null], \"passed\": true}, {\"check\": \"else null\", \"actual\": [null], \"expected\": [null], \"passed\": true}, {\"check\": \"empty vector\", \"actual\": [], \"expected\": [], \"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."}}