{"abstract":"Deque borrow release retains already-reclaimed storage in its pending list.","category":"Bounded deques","checks":7,"contract":"Release a unique deque borrow token. Retired storage is reclaimed only when both the owner and all borrowers are gone; unknown releases are idempotent. Return active pins, receipt, retired/reclaimed sets, reclamation epoch and owner state.","evaluation_group":"s3-bounded-deques-borrow-release","failed_approach":"The partial repair still applies the incorrect transition to an admitted boundary or multi-element case.","family":"s3-bounded-deques-borrow-release-pending-clear","id":"FA-46976","implementations":{"attempt":{"sha256":"3e493db2c32bc3e821a620ac13c0089c785e81d09489664162a6cab4f30a07b2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    pins,token,owner,retired,epoch=x\n    found=any(p[0]==token for p in pins)\n    active=[p for p in pins if p[0]!=token]\n    can_reclaim=not active and not owner\n    reclaimed=retired[:] if can_reclaim else []\n    pending=[] if len(reclaimed)==1 else retired[:]\n    version=epoch+(found and bool(reclaimed))\n    return [active,found,pending,reclaimed,version,bool(active),owner]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([[[1,N],[2,N+1]],1,False,[4,5],2]), {1: [[[2, 2]], True, [4, 5], [], 2, True, False], 2: [[[2, 3]], True, [4, 5], [], 2, True, False], 3: [[[2, 4]], True, [4, 5], [], 2, True, False], 4: [[[2, 5]], True, [4, 5], [], 2, True, False], 5: [[[2, 6]], True, [4, 5], [], 2, True, False]}[N])\ncheck('1', solve([[[1,N]],1,False,[4,5],2]), {1: [[], True, [], [4, 5], 3, False, False], 2: [[], True, [], [4, 5], 3, False, False], 3: [[], True, [], [4, 5], 3, False, False], 4: [[], True, [], [4, 5], 3, False, False], 5: [[], True, [], [4, 5], 3, False, False]}[N])\ncheck('2', solve([[[1,N]],1,True,[4],3]), {1: [[], True, [4], [], 3, False, True], 2: [[], True, [4], [], 3, False, True], 3: [[], True, [4], [], 3, False, True], 4: [[], True, [4], [], 3, False, True], 5: [[], True, [4], [], 3, False, True]}[N])\ncheck('3', solve([[[1,N]],9,False,[4],1]), {1: [[[1, 1]], False, [4], [], 1, True, False], 2: [[[1, 2]], False, [4], [], 1, True, False], 3: [[[1, 3]], False, [4], [], 1, True, False], 4: [[[1, 4]], False, [4], [], 1, True, False], 5: [[[1, 5]], False, [4], [], 1, True, False]}[N])\ncheck('4', solve([[],9,True,[],0]), {1: [[], False, [], [], 0, False, True], 2: [[], False, [], [], 0, False, True], 3: [[], False, [], [], 0, False, True], 4: [[], False, [], [], 0, False, True], 5: [[], False, [], [], 0, False, True]}[N])\ncheck('5', solve([[[1,N],[2,N+1]],2,False,[],4]), {1: [[[1, 1]], True, [], [], 4, True, False], 2: [[[1, 2]], True, [], [], 4, True, False], 3: [[[1, 3]], True, [], [], 4, True, False], 4: [[[1, 4]], True, [], [], 4, True, False], 5: [[[1, 5]], True, [], [], 4, True, False]}[N])\ncheck('pin identity differs from payload', solve([[[17,N],[18,N+1]],17,False,[4],3]), [[[18,N+1]],True,[4],[],3,True,False])\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":"20c4b5d729eee8b2ff6aef37adaae83d7a95f83f08045915cbc137a7ab764652","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    pins,token,owner,retired,epoch=x\n    found=any(p[0]==token for p in pins)\n    active=[p for p in pins if p[0]!=token]\n    can_reclaim=not active and not owner\n    reclaimed=retired[:] if can_reclaim else []\n    pending=retired[:]\n    version=epoch+(found and bool(reclaimed))\n    return [active,found,pending,reclaimed,version,bool(active),owner]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([[[1,N],[2,N+1]],1,False,[4,5],2]), {1: [[[2, 2]], True, [4, 5], [], 2, True, False], 2: [[[2, 3]], True, [4, 5], [], 2, True, False], 3: [[[2, 4]], True, [4, 5], [], 2, True, False], 4: [[[2, 5]], True, [4, 5], [], 2, True, False], 5: [[[2, 6]], True, [4, 5], [], 2, True, False]}[N])\ncheck('1', solve([[[1,N]],1,False,[4,5],2]), {1: [[], True, [], [4, 5], 3, False, False], 2: [[], True, [], [4, 5], 3, False, False], 3: [[], True, [], [4, 5], 3, False, False], 4: [[], True, [], [4, 5], 3, False, False], 5: [[], True, [], [4, 5], 3, False, False]}[N])\ncheck('2', solve([[[1,N]],1,True,[4],3]), {1: [[], True, [4], [], 3, False, True], 2: [[], True, [4], [], 3, False, True], 3: [[], True, [4], [], 3, False, True], 4: [[], True, [4], [], 3, False, True], 5: [[], True, [4], [], 3, False, True]}[N])\ncheck('3', solve([[[1,N]],9,False,[4],1]), {1: [[[1, 1]], False, [4], [], 1, True, False], 2: [[[1, 2]], False, [4], [], 1, True, False], 3: [[[1, 3]], False, [4], [], 1, True, False], 4: [[[1, 4]], False, [4], [], 1, True, False], 5: [[[1, 5]], False, [4], [], 1, True, False]}[N])\ncheck('4', solve([[],9,True,[],0]), {1: [[], False, [], [], 0, False, True], 2: [[], False, [], [], 0, False, True], 3: [[], False, [], [], 0, False, True], 4: [[], False, [], [], 0, False, True], 5: [[], False, [], [], 0, False, True]}[N])\ncheck('5', solve([[[1,N],[2,N+1]],2,False,[],4]), {1: [[[1, 1]], True, [], [], 4, True, False], 2: [[[1, 2]], True, [], [], 4, True, False], 3: [[[1, 3]], True, [], [], 4, True, False], 4: [[[1, 4]], True, [], [], 4, True, False], 5: [[[1, 5]], True, [], [], 4, True, False]}[N])\ncheck('pin identity differs from payload', solve([[[17,N],[18,N+1]],17,False,[4],3]), [[[18,N+1]],True,[4],[],3,True,False])\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":"dcbd3052aa1d8f3461cc96d7e19f675448e4c29c970ae15407bc7127f44713d2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    pins,token,owner,retired,epoch=x\n    found=any(p[0]==token for p in pins)\n    active=[p for p in pins if p[0]!=token]\n    can_reclaim=not active and not owner\n    reclaimed=retired[:] if can_reclaim else []\n    pending=[] if reclaimed else retired[:]\n    version=epoch+(found and bool(reclaimed))\n    return [active,found,pending,reclaimed,version,bool(active),owner]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([[[1,N],[2,N+1]],1,False,[4,5],2]), {1: [[[2, 2]], True, [4, 5], [], 2, True, False], 2: [[[2, 3]], True, [4, 5], [], 2, True, False], 3: [[[2, 4]], True, [4, 5], [], 2, True, False], 4: [[[2, 5]], True, [4, 5], [], 2, True, False], 5: [[[2, 6]], True, [4, 5], [], 2, True, False]}[N])\ncheck('1', solve([[[1,N]],1,False,[4,5],2]), {1: [[], True, [], [4, 5], 3, False, False], 2: [[], True, [], [4, 5], 3, False, False], 3: [[], True, [], [4, 5], 3, False, False], 4: [[], True, [], [4, 5], 3, False, False], 5: [[], True, [], [4, 5], 3, False, False]}[N])\ncheck('2', solve([[[1,N]],1,True,[4],3]), {1: [[], True, [4], [], 3, False, True], 2: [[], True, [4], [], 3, False, True], 3: [[], True, [4], [], 3, False, True], 4: [[], True, [4], [], 3, False, True], 5: [[], True, [4], [], 3, False, True]}[N])\ncheck('3', solve([[[1,N]],9,False,[4],1]), {1: [[[1, 1]], False, [4], [], 1, True, False], 2: [[[1, 2]], False, [4], [], 1, True, False], 3: [[[1, 3]], False, [4], [], 1, True, False], 4: [[[1, 4]], False, [4], [], 1, True, False], 5: [[[1, 5]], False, [4], [], 1, True, False]}[N])\ncheck('4', solve([[],9,True,[],0]), {1: [[], False, [], [], 0, False, True], 2: [[], False, [], [], 0, False, True], 3: [[], False, [], [], 0, False, True], 4: [[], False, [], [], 0, False, True], 5: [[], False, [], [], 0, False, True]}[N])\ncheck('5', solve([[[1,N],[2,N+1]],2,False,[],4]), {1: [[[1, 1]], True, [], [], 4, True, False], 2: [[[1, 2]], True, [], [], 4, True, False], 3: [[[1, 3]], True, [], [], 4, True, False], 4: [[[1, 4]], True, [], [], 4, True, False], 5: [[[1, 5]], True, [], [], 4, True, False]}[N])\ncheck('pin identity differs from payload', solve([[[17,N],[18,N+1]],17,False,[4],3]), [[[18,N+1]],True,[4],[],3,True,False])\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-borrow-release-pending-clear","generated_at":"2026-09-29T14:44:37.148564+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.","repair":"Restore the documented pending clear invariant in borrow-release.","root_cause":"Deque borrow release retains already-reclaimed storage in its pending list.","sha256":"b45c7a90519d86d74a74c5b42014d7480091b6cc97c34b9ae009c8feb093b875","title":"Deque borrow release retains already-reclaimed storage in its pending list · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.05,"exit_code":1,"observations":[{"actual":[[[2,2]],true,[4,5],[],2,true,false],"check":"0","expected":[[[2,2]],true,[4,5],[],2,true,false],"passed":true},{"actual":[[],true,[4,5],[4,5],3,false,false],"check":"1","expected":[[],true,[],[4,5],3,false,false],"passed":false},{"actual":[[],true,[4],[],3,false,true],"check":"2","expected":[[],true,[4],[],3,false,true],"passed":true},{"actual":[[[1,1]],false,[4],[],1,true,false],"check":"3","expected":[[[1,1]],false,[4],[],1,true,false],"passed":true},{"actual":[[],false,[],[],0,false,true],"check":"4","expected":[[],false,[],[],0,false,true],"passed":true},{"actual":[[[1,1]],true,[],[],4,true,false],"check":"5","expected":[[[1,1]],true,[],[],4,true,false],"passed":true},{"actual":[[[18,2]],true,[4],[],3,true,false],"check":"pin identity differs from payload","expected":[[[18,2]],true,[4],[],3,true,false],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[[2, 2]], true, [4, 5], [], 2, true, false], \"expected\": [[[2, 2]], true, [4, 5], [], 2, true, false], \"passed\": true}, {\"check\": \"1\", \"actual\": [[], true, [4, 5], [4, 5], 3, false, false], \"expected\": [[], true, [], [4, 5], 3, false, false], \"passed\": false}, {\"check\": \"2\", \"actual\": [[], true, [4], [], 3, false, true], \"expected\": [[], true, [4], [], 3, false, true], \"passed\": true}, {\"check\": \"3\", \"actual\": [[[1, 1]], false, [4], [], 1, true, false], \"expected\": [[[1, 1]], false, [4], [], 1, true, false], \"passed\": true}, {\"check\": \"4\", \"actual\": [[], false, [], [], 0, false, true], \"expected\": [[], false, [], [], 0, false, true], \"passed\": true}, {\"check\": \"5\", \"actual\": [[[1, 1]], true, [], [], 4, true, false], \"expected\": [[[1, 1]], true, [], [], 4, true, false], \"passed\": true}, {\"check\": \"pin identity differs from payload\", \"actual\": [[[18, 2]], true, [4], [], 3, true, false], \"expected\": [[[18, 2]], true, [4], [], 3, true, false], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.754,"exit_code":1,"observations":[{"actual":[[[2,2]],true,[4,5],[],2,true,false],"check":"0","expected":[[[2,2]],true,[4,5],[],2,true,false],"passed":true},{"actual":[[],true,[4,5],[4,5],3,false,false],"check":"1","expected":[[],true,[],[4,5],3,false,false],"passed":false},{"actual":[[],true,[4],[],3,false,true],"check":"2","expected":[[],true,[4],[],3,false,true],"passed":true},{"actual":[[[1,1]],false,[4],[],1,true,false],"check":"3","expected":[[[1,1]],false,[4],[],1,true,false],"passed":true},{"actual":[[],false,[],[],0,false,true],"check":"4","expected":[[],false,[],[],0,false,true],"passed":true},{"actual":[[[1,1]],true,[],[],4,true,false],"check":"5","expected":[[[1,1]],true,[],[],4,true,false],"passed":true},{"actual":[[[18,2]],true,[4],[],3,true,false],"check":"pin identity differs from payload","expected":[[[18,2]],true,[4],[],3,true,false],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[[2, 2]], true, [4, 5], [], 2, true, false], \"expected\": [[[2, 2]], true, [4, 5], [], 2, true, false], \"passed\": true}, {\"check\": \"1\", \"actual\": [[], true, [4, 5], [4, 5], 3, false, false], \"expected\": [[], true, [], [4, 5], 3, false, false], \"passed\": false}, {\"check\": \"2\", \"actual\": [[], true, [4], [], 3, false, true], \"expected\": [[], true, [4], [], 3, false, true], \"passed\": true}, {\"check\": \"3\", \"actual\": [[[1, 1]], false, [4], [], 1, true, false], \"expected\": [[[1, 1]], false, [4], [], 1, true, false], \"passed\": true}, {\"check\": \"4\", \"actual\": [[], false, [], [], 0, false, true], \"expected\": [[], false, [], [], 0, false, true], \"passed\": true}, {\"check\": \"5\", \"actual\": [[[1, 1]], true, [], [], 4, true, false], \"expected\": [[[1, 1]], true, [], [], 4, true, false], \"passed\": true}, {\"check\": \"pin identity differs from payload\", \"actual\": [[[18, 2]], true, [4], [], 3, true, false], \"expected\": [[[18, 2]], true, [4], [], 3, true, false], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.158,"exit_code":0,"observations":[{"actual":[[[2,2]],true,[4,5],[],2,true,false],"check":"0","expected":[[[2,2]],true,[4,5],[],2,true,false],"passed":true},{"actual":[[],true,[],[4,5],3,false,false],"check":"1","expected":[[],true,[],[4,5],3,false,false],"passed":true},{"actual":[[],true,[4],[],3,false,true],"check":"2","expected":[[],true,[4],[],3,false,true],"passed":true},{"actual":[[[1,1]],false,[4],[],1,true,false],"check":"3","expected":[[[1,1]],false,[4],[],1,true,false],"passed":true},{"actual":[[],false,[],[],0,false,true],"check":"4","expected":[[],false,[],[],0,false,true],"passed":true},{"actual":[[[1,1]],true,[],[],4,true,false],"check":"5","expected":[[[1,1]],true,[],[],4,true,false],"passed":true},{"actual":[[[18,2]],true,[4],[],3,true,false],"check":"pin identity differs from payload","expected":[[[18,2]],true,[4],[],3,true,false],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [[[2, 2]], true, [4, 5], [], 2, true, false], \"expected\": [[[2, 2]], true, [4, 5], [], 2, true, false], \"passed\": true}, {\"check\": \"1\", \"actual\": [[], true, [], [4, 5], 3, false, false], \"expected\": [[], true, [], [4, 5], 3, false, false], \"passed\": true}, {\"check\": \"2\", \"actual\": [[], true, [4], [], 3, false, true], \"expected\": [[], true, [4], [], 3, false, true], \"passed\": true}, {\"check\": \"3\", \"actual\": [[[1, 1]], false, [4], [], 1, true, false], \"expected\": [[[1, 1]], false, [4], [], 1, true, false], \"passed\": true}, {\"check\": \"4\", \"actual\": [[], false, [], [], 0, false, true], \"expected\": [[], false, [], [], 0, false, true], \"passed\": true}, {\"check\": \"5\", \"actual\": [[[1, 1]], true, [], [], 4, true, false], \"expected\": [[[1, 1]], true, [], [], 4, true, false], \"passed\": true}, {\"check\": \"pin identity differs from payload\", \"actual\": [[[18, 2]], true, [4], [], 3, true, false], \"expected\": [[[18, 2]], true, [4], [], 3, true, false], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}