{"abstract":"Deque uniqueness accidentally returns duplicate positions as survivors.","category":"Bounded deques","checks":6,"contract":"Keep the first occurrence of each deque payload and return survivor values plus original positions removed. Payload equality is integer equality; zero is a valid value.","contract_signature":"x","evaluation_group":"s3-bounded-deques-stable-unique","failed_approach":"The partial repair still applies the incorrect transition to an admitted boundary or multi-element case.","family":"s3-bounded-deques-stable-unique-duplicate-visibility","id":"FA-46356","implementations":{"attempt":{"sha256":"eecb417ca26d6f2140ec042adf6a171dcc70c3686f58de82c82ec1fe20f8bcf8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    items=x\n    seen=set()\n    keep=[]\n    removed=[]\n    for i,v in enumerate(items):\n        if v in seen:removed.append(i)\n        else:\n            keep.append(v)\n            seen.add(v)\n    return [keep if len(seen)<=1 else items,removed]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([N,N+1,N,N+2,N+1]), {1: [[1, 2, 3], [2, 4]], 2: [[2, 3, 4], [2, 4]], 3: [[3, 4, 5], [2, 4]], 4: [[4, 5, 6], [2, 4]], 5: [[5, 6, 7], [2, 4]]}[N])\ncheck('1', solve([0,N,0,N]), {1: [[0, 1], [2, 3]], 2: [[0, 2], [2, 3]], 3: [[0, 3], [2, 3]], 4: [[0, 4], [2, 3]], 5: [[0, 5], [2, 3]]}[N])\ncheck('2', solve([N,N,N]), {1: [[1], [1, 2]], 2: [[2], [1, 2]], 3: [[3], [1, 2]], 4: [[4], [1, 2]], 5: [[5], [1, 2]]}[N])\ncheck('3', solve([]), {1: [[], []], 2: [[], []], 3: [[], []], 4: [[], []], 5: [[], []]}[N])\ncheck('4', solve([N,N+1,N+2]), {1: [[1, 2, 3], []], 2: [[2, 3, 4], []], 3: [[3, 4, 5], []], 4: [[4, 5, 6], []], 5: [[5, 6, 7], []]}[N])\ncheck('5', solve([N+2,N,N+2,N+1]), {1: [[3, 1, 2], [2]], 2: [[4, 2, 3], [2]], 3: [[5, 3, 4], [2]], 4: [[6, 4, 5], [2]], 5: [[7, 5, 6], [2]]}[N])\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":"95dd5741dc5761fac01c6f80a165f606db036032110f29e6348ec09645b1c4ce","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    items=x\n    seen=set()\n    keep=[]\n    removed=[]\n    for i,v in enumerate(items):\n        if v in seen:removed.append(i)\n        else:\n            keep.append(v)\n            seen.add(v)\n    return [items,removed]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([N,N+1,N,N+2,N+1]), {1: [[1, 2, 3], [2, 4]], 2: [[2, 3, 4], [2, 4]], 3: [[3, 4, 5], [2, 4]], 4: [[4, 5, 6], [2, 4]], 5: [[5, 6, 7], [2, 4]]}[N])\ncheck('1', solve([0,N,0,N]), {1: [[0, 1], [2, 3]], 2: [[0, 2], [2, 3]], 3: [[0, 3], [2, 3]], 4: [[0, 4], [2, 3]], 5: [[0, 5], [2, 3]]}[N])\ncheck('2', solve([N,N,N]), {1: [[1], [1, 2]], 2: [[2], [1, 2]], 3: [[3], [1, 2]], 4: [[4], [1, 2]], 5: [[5], [1, 2]]}[N])\ncheck('3', solve([]), {1: [[], []], 2: [[], []], 3: [[], []], 4: [[], []], 5: [[], []]}[N])\ncheck('4', solve([N,N+1,N+2]), {1: [[1, 2, 3], []], 2: [[2, 3, 4], []], 3: [[3, 4, 5], []], 4: [[4, 5, 6], []], 5: [[5, 6, 7], []]}[N])\ncheck('5', solve([N+2,N,N+2,N+1]), {1: [[3, 1, 2], [2]], 2: [[4, 2, 3], [2]], 3: [[5, 3, 4], [2]], 4: [[6, 4, 5], [2]], 5: [[7, 5, 6], [2]]}[N])\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 finite deterministic model; no claim of production implementation or concurrent memory-model conformance. 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-bounded-deques-stable-unique-duplicate-visibility","generated_at":"2026-09-29T14:44:31.228873+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Controlled bounded deque implementation model with explicit storage and lifecycle observations.","root_cause":"Deque uniqueness accidentally returns duplicate positions as survivors.","sha256":"204212f8cbf946c720cb75e7cb549711a7e58b63994b5eeac9c1c7c5e488e295","title":"Deque uniqueness accidentally returns duplicate positions as survivors · 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":40.719,"exit_code":1,"observations":[{"actual":[[1,2,1,3,2],[2,4]],"check":"0","expected":[[1,2,3],[2,4]],"passed":false},{"actual":[[0,1,0,1],[2,3]],"check":"1","expected":[[0,1],[2,3]],"passed":false},{"actual":[[1],[1,2]],"check":"2","expected":[[1],[1,2]],"passed":true},{"actual":[[],[]],"check":"3","expected":[[],[]],"passed":true},{"actual":[[1,2,3],[]],"check":"4","expected":[[1,2,3],[]],"passed":true},{"actual":[[3,1,3,2],[2]],"check":"5","expected":[[3,1,2],[2]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[1, 2, 1, 3, 2], [2, 4]], \"expected\": [[1, 2, 3], [2, 4]], \"passed\": false}, {\"check\": \"1\", \"actual\": [[0, 1, 0, 1], [2, 3]], \"expected\": [[0, 1], [2, 3]], \"passed\": false}, {\"check\": \"2\", \"actual\": [[1], [1, 2]], \"expected\": [[1], [1, 2]], \"passed\": true}, {\"check\": \"3\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"4\", \"actual\": [[1, 2, 3], []], \"expected\": [[1, 2, 3], []], \"passed\": true}, {\"check\": \"5\", \"actual\": [[3, 1, 3, 2], [2]], \"expected\": [[3, 1, 2], [2]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.609,"exit_code":1,"observations":[{"actual":[[1,2,1,3,2],[2,4]],"check":"0","expected":[[1,2,3],[2,4]],"passed":false},{"actual":[[0,1,0,1],[2,3]],"check":"1","expected":[[0,1],[2,3]],"passed":false},{"actual":[[1,1,1],[1,2]],"check":"2","expected":[[1],[1,2]],"passed":false},{"actual":[[],[]],"check":"3","expected":[[],[]],"passed":true},{"actual":[[1,2,3],[]],"check":"4","expected":[[1,2,3],[]],"passed":true},{"actual":[[3,1,3,2],[2]],"check":"5","expected":[[3,1,2],[2]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[1, 2, 1, 3, 2], [2, 4]], \"expected\": [[1, 2, 3], [2, 4]], \"passed\": false}, {\"check\": \"1\", \"actual\": [[0, 1, 0, 1], [2, 3]], \"expected\": [[0, 1], [2, 3]], \"passed\": false}, {\"check\": \"2\", \"actual\": [[1, 1, 1], [1, 2]], \"expected\": [[1], [1, 2]], \"passed\": false}, {\"check\": \"3\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"4\", \"actual\": [[1, 2, 3], []], \"expected\": [[1, 2, 3], []], \"passed\": true}, {\"check\": \"5\", \"actual\": [[3, 1, 3, 2], [2]], \"expected\": [[3, 1, 2], [2]], \"passed\": false}], \"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."}}