{"abstract":"Retractions carry the new value instead of the old value.","category":"Data systems","checks":8,"contract":"Convert a sequence of [id,before,after] updates into signed filtered rows, with None denoting absent row. The predicate is value>=cutoff. Emit qualifying before-images negatively before qualifying after-images positively; suppress unchanged qualifying values.","contract_signature":"d","evaluation_group":"s3-data-systems-delta-filter-before-after","failed_approach":"Using the threshold as a placeholder cannot retract the stored row.","family":"s3-data-systems-delta-filter-before-after-before-payload","id":"FA-44686","implementations":{"attempt":{"sha256":"1ac49ddd7bdf67ad051d38e12b7dcbf1f9296f06c942f9a6f8b8a5fc63cba6cf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        cutoff,updates=d\n        out=[]\n        for ident,before,after in updates:\n            old=before is not None and before>=cutoff\n            new=after is not None and after>=cutoff\n            if old and new and before==after: continue\n            if old: out.append([ident,cutoff,-1])\n            if new: out.append([ident,after,1])\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('leaves filter', solve([1, [[7, 3, 0]]]), [[7, 3, -1]])\n    check('enters filter', solve([1, [[7, 0, 3]]]), [[7, 3, 1]])\n    check('changes within filter', solve([1, [[7, 2, 3]]]), [[7, 2, -1], [7, 3, 1]])\n    check('unchanged', solve([1, [[7, 1, 1]]]), [])\n    check('insert', solve([1, [[7, None, 2]]]), [[7, 2, 1]])\n    check('delete', solve([1, [[7, 2, None]]]), [[7, 2, -1]])\n    check('outside both', solve([1, [[7, -1, 0]]]), [])\n    check('no updates', solve([1, []]), [])\nelif N == 2:\n    check('leaves filter', solve([2, [[7, 4, 1]]]), [[7, 4, -1]])\n    check('enters filter', solve([2, [[7, 1, 4]]]), [[7, 4, 1]])\n    check('changes within filter', solve([2, [[7, 3, 4]]]), [[7, 3, -1], [7, 4, 1]])\n    check('unchanged', solve([2, [[7, 2, 2]]]), [])\n    check('insert', solve([2, [[7, None, 3]]]), [[7, 3, 1]])\n    check('delete', solve([2, [[7, 3, None]]]), [[7, 3, -1]])\n    check('outside both', solve([2, [[7, 0, 1]]]), [])\n    check('no updates', solve([2, []]), [])\nelif N == 3:\n    check('leaves filter', solve([3, [[7, 5, 2]]]), [[7, 5, -1]])\n    check('enters filter', solve([3, [[7, 2, 5]]]), [[7, 5, 1]])\n    check('changes within filter', solve([3, [[7, 4, 5]]]), [[7, 4, -1], [7, 5, 1]])\n    check('unchanged', solve([3, [[7, 3, 3]]]), [])\n    check('insert', solve([3, [[7, None, 4]]]), [[7, 4, 1]])\n    check('delete', solve([3, [[7, 4, None]]]), [[7, 4, -1]])\n    check('outside both', solve([3, [[7, 1, 2]]]), [])\n    check('no updates', solve([3, []]), [])\nelif N == 4:\n    check('leaves filter', solve([4, [[7, 6, 3]]]), [[7, 6, -1]])\n    check('enters filter', solve([4, [[7, 3, 6]]]), [[7, 6, 1]])\n    check('changes within filter', solve([4, [[7, 5, 6]]]), [[7, 5, -1], [7, 6, 1]])\n    check('unchanged', solve([4, [[7, 4, 4]]]), [])\n    check('insert', solve([4, [[7, None, 5]]]), [[7, 5, 1]])\n    check('delete', solve([4, [[7, 5, None]]]), [[7, 5, -1]])\n    check('outside both', solve([4, [[7, 2, 3]]]), [])\n    check('no updates', solve([4, []]), [])\nelif N == 5:\n    check('leaves filter', solve([5, [[7, 7, 4]]]), [[7, 7, -1]])\n    check('enters filter', solve([5, [[7, 4, 7]]]), [[7, 7, 1]])\n    check('changes within filter', solve([5, [[7, 6, 7]]]), [[7, 6, -1], [7, 7, 1]])\n    check('unchanged', solve([5, [[7, 5, 5]]]), [])\n    check('insert', solve([5, [[7, None, 6]]]), [[7, 6, 1]])\n    check('delete', solve([5, [[7, 6, None]]]), [[7, 6, -1]])\n    check('outside both', solve([5, [[7, 3, 4]]]), [])\n    check('no updates', solve([5, []]), [])\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":"d753567c8441496d76eaa785bf76268415040d8fc0eedea68baa4ab01b5b4c7f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(d):\n    try:\n        cutoff,updates=d\n        out=[]\n        for ident,before,after in updates:\n            old=before is not None and before>=cutoff\n            new=after is not None and after>=cutoff\n            if old and new and before==after: continue\n            if old: out.append([ident,after,-1])\n            if new: out.append([ident,after,1])\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('leaves filter', solve([1, [[7, 3, 0]]]), [[7, 3, -1]])\n    check('enters filter', solve([1, [[7, 0, 3]]]), [[7, 3, 1]])\n    check('changes within filter', solve([1, [[7, 2, 3]]]), [[7, 2, -1], [7, 3, 1]])\n    check('unchanged', solve([1, [[7, 1, 1]]]), [])\n    check('insert', solve([1, [[7, None, 2]]]), [[7, 2, 1]])\n    check('delete', solve([1, [[7, 2, None]]]), [[7, 2, -1]])\n    check('outside both', solve([1, [[7, -1, 0]]]), [])\n    check('no updates', solve([1, []]), [])\nelif N == 2:\n    check('leaves filter', solve([2, [[7, 4, 1]]]), [[7, 4, -1]])\n    check('enters filter', solve([2, [[7, 1, 4]]]), [[7, 4, 1]])\n    check('changes within filter', solve([2, [[7, 3, 4]]]), [[7, 3, -1], [7, 4, 1]])\n    check('unchanged', solve([2, [[7, 2, 2]]]), [])\n    check('insert', solve([2, [[7, None, 3]]]), [[7, 3, 1]])\n    check('delete', solve([2, [[7, 3, None]]]), [[7, 3, -1]])\n    check('outside both', solve([2, [[7, 0, 1]]]), [])\n    check('no updates', solve([2, []]), [])\nelif N == 3:\n    check('leaves filter', solve([3, [[7, 5, 2]]]), [[7, 5, -1]])\n    check('enters filter', solve([3, [[7, 2, 5]]]), [[7, 5, 1]])\n    check('changes within filter', solve([3, [[7, 4, 5]]]), [[7, 4, -1], [7, 5, 1]])\n    check('unchanged', solve([3, [[7, 3, 3]]]), [])\n    check('insert', solve([3, [[7, None, 4]]]), [[7, 4, 1]])\n    check('delete', solve([3, [[7, 4, None]]]), [[7, 4, -1]])\n    check('outside both', solve([3, [[7, 1, 2]]]), [])\n    check('no updates', solve([3, []]), [])\nelif N == 4:\n    check('leaves filter', solve([4, [[7, 6, 3]]]), [[7, 6, -1]])\n    check('enters filter', solve([4, [[7, 3, 6]]]), [[7, 6, 1]])\n    check('changes within filter', solve([4, [[7, 5, 6]]]), [[7, 5, -1], [7, 6, 1]])\n    check('unchanged', solve([4, [[7, 4, 4]]]), [])\n    check('insert', solve([4, [[7, None, 5]]]), [[7, 5, 1]])\n    check('delete', solve([4, [[7, 5, None]]]), [[7, 5, -1]])\n    check('outside both', solve([4, [[7, 2, 3]]]), [])\n    check('no updates', solve([4, []]), [])\nelif N == 5:\n    check('leaves filter', solve([5, [[7, 7, 4]]]), [[7, 7, -1]])\n    check('enters filter', solve([5, [[7, 4, 7]]]), [[7, 7, 1]])\n    check('changes within filter', solve([5, [[7, 6, 7]]]), [[7, 6, -1], [7, 7, 1]])\n    check('unchanged', solve([5, [[7, 5, 5]]]), [])\n    check('insert', solve([5, [[7, None, 6]]]), [[7, 6, 1]])\n    check('delete', solve([5, [[7, 6, None]]]), [[7, 6, -1]])\n    check('outside both', solve([5, [[7, 3, 4]]]), [])\n    check('no updates', solve([5, []]), [])\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-delta-filter-before-after-before-payload","generated_at":"2026-09-29T14:44:14.755280+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":"delta-filter-before-after: Retractions carry the new value instead of the old value.","sha256":"97b47e7644870e6c0cbb6598e5899429c3cf3a8c010896dccc0733cca489a08d","title":"Retractions carry the new value instead of the old value · 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":40.014,"exit_code":1,"observations":[{"actual":[[7,1,-1]],"check":"leaves filter","expected":[[7,3,-1]],"passed":false},{"actual":[[7,3,1]],"check":"enters filter","expected":[[7,3,1]],"passed":true},{"actual":[[7,1,-1],[7,3,1]],"check":"changes within filter","expected":[[7,2,-1],[7,3,1]],"passed":false},{"actual":[],"check":"unchanged","expected":[],"passed":true},{"actual":[[7,2,1]],"check":"insert","expected":[[7,2,1]],"passed":true},{"actual":[[7,1,-1]],"check":"delete","expected":[[7,2,-1]],"passed":false},{"actual":[],"check":"outside both","expected":[],"passed":true},{"actual":[],"check":"no updates","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"leaves filter\", \"actual\": [[7, 1, -1]], \"expected\": [[7, 3, -1]], \"passed\": false}, {\"check\": \"enters filter\", \"actual\": [[7, 3, 1]], \"expected\": [[7, 3, 1]], \"passed\": true}, {\"check\": \"changes within filter\", \"actual\": [[7, 1, -1], [7, 3, 1]], \"expected\": [[7, 2, -1], [7, 3, 1]], \"passed\": false}, {\"check\": \"unchanged\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"insert\", \"actual\": [[7, 2, 1]], \"expected\": [[7, 2, 1]], \"passed\": true}, {\"check\": \"delete\", \"actual\": [[7, 1, -1]], \"expected\": [[7, 2, -1]], \"passed\": false}, {\"check\": \"outside both\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"no updates\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.769,"exit_code":1,"observations":[{"actual":[[7,0,-1]],"check":"leaves filter","expected":[[7,3,-1]],"passed":false},{"actual":[[7,3,1]],"check":"enters filter","expected":[[7,3,1]],"passed":true},{"actual":[[7,3,-1],[7,3,1]],"check":"changes within filter","expected":[[7,2,-1],[7,3,1]],"passed":false},{"actual":[],"check":"unchanged","expected":[],"passed":true},{"actual":[[7,2,1]],"check":"insert","expected":[[7,2,1]],"passed":true},{"actual":[[7,null,-1]],"check":"delete","expected":[[7,2,-1]],"passed":false},{"actual":[],"check":"outside both","expected":[],"passed":true},{"actual":[],"check":"no updates","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"leaves filter\", \"actual\": [[7, 0, -1]], \"expected\": [[7, 3, -1]], \"passed\": false}, {\"check\": \"enters filter\", \"actual\": [[7, 3, 1]], \"expected\": [[7, 3, 1]], \"passed\": true}, {\"check\": \"changes within filter\", \"actual\": [[7, 3, -1], [7, 3, 1]], \"expected\": [[7, 2, -1], [7, 3, 1]], \"passed\": false}, {\"check\": \"unchanged\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"insert\", \"actual\": [[7, 2, 1]], \"expected\": [[7, 2, 1]], \"passed\": true}, {\"check\": \"delete\", \"actual\": [[7, null, -1]], \"expected\": [[7, 2, -1]], \"passed\": false}, {\"check\": \"outside both\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"no updates\", \"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."}}