{"abstract":"Deque shrink reallocates while a storage borrow exists.","category":"Bounded deques","checks":8,"contract":"A bounded deque shrinks by half, floored by live size and a minimum allocation, only at or below low occupancy, with no borrows and with resulting capacity at least the configured high watermark. Unchanged allocations keep epoch.","evaluation_group":"s3-bounded-deques-shrink-hysteresis","failed_approach":"The partial repair still applies the incorrect transition to an admitted boundary or multi-element case.","family":"s3-bounded-deques-shrink-hysteresis-pin-barrier","id":"FA-47146","implementations":{"attempt":{"sha256":"77c6a5ea2cb702cbb43f34e35ea39e01abce260662966108277722531d577682","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    cap,size,minimum,low,high,pins,epoch=x\n    target=max(minimum,max(size,cap//2))\n    allowed=size<=low and cap>minimum and (not pins or size<low) and target>=high\n    capacity=target if allowed else cap\n    version=epoch+allowed\n    free=capacity-size\n    return [capacity,allowed,version,free,low,high,pins]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([16,3,4,4,7,0,N]), {1: [8, True, 2, 5, 4, 7, 0], 2: [8, True, 3, 5, 4, 7, 0], 3: [8, True, 4, 5, 4, 7, 0], 4: [8, True, 5, 5, 4, 7, 0], 5: [8, True, 6, 5, 4, 7, 0]}[N])\ncheck('1', solve([16,4,4,4,8,0,N]), {1: [8, True, 2, 4, 4, 8, 0], 2: [8, True, 3, 4, 4, 8, 0], 3: [8, True, 4, 4, 4, 8, 0], 4: [8, True, 5, 4, 4, 8, 0], 5: [8, True, 6, 4, 4, 8, 0]}[N])\ncheck('2', solve([16,3,4,4,9,0,N]), {1: [16, False, 1, 13, 4, 9, 0], 2: [16, False, 2, 13, 4, 9, 0], 3: [16, False, 3, 13, 4, 9, 0], 4: [16, False, 4, 13, 4, 9, 0], 5: [16, False, 5, 13, 4, 9, 0]}[N])\ncheck('3', solve([16,3,4,4,7,1,N]), {1: [16, False, 1, 13, 4, 7, 1], 2: [16, False, 2, 13, 4, 7, 1], 3: [16, False, 3, 13, 4, 7, 1], 4: [16, False, 4, 13, 4, 7, 1], 5: [16, False, 5, 13, 4, 7, 1]}[N])\ncheck('4', solve([4,1,4,2,2,0,N]), {1: [4, False, 1, 3, 2, 2, 0], 2: [4, False, 2, 3, 2, 2, 0], 3: [4, False, 3, 3, 2, 2, 0], 4: [4, False, 4, 3, 2, 2, 0], 5: [4, False, 5, 3, 2, 2, 0]}[N])\ncheck('5', solve([12,7,4,8,6,0,N]), {1: [7, True, 2, 0, 8, 6, 0], 2: [7, True, 3, 0, 8, 6, 0], 3: [7, True, 4, 0, 8, 6, 0], 4: [7, True, 5, 0, 8, 6, 0], 5: [7, True, 6, 0, 8, 6, 0]}[N])\ncheck('6', solve([12,2,8,3,7,0,N]), {1: [8, True, 2, 6, 3, 7, 0], 2: [8, True, 3, 6, 3, 7, 0], 3: [8, True, 4, 6, 3, 7, 0], 4: [8, True, 5, 6, 3, 7, 0], 5: [8, True, 6, 6, 3, 7, 0]}[N])\ncheck('7', solve([16,5,4,4,6,0,N]), {1: [16, False, 1, 11, 4, 6, 0], 2: [16, False, 2, 11, 4, 6, 0], 3: [16, False, 3, 11, 4, 6, 0], 4: [16, False, 4, 11, 4, 6, 0], 5: [16, False, 5, 11, 4, 6, 0]}[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":"7c8a2e595242fa8a19b8503780c525fae3f0e07e6eb0a36a63e4e557ff7047bc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    cap,size,minimum,low,high,pins,epoch=x\n    target=max(minimum,max(size,cap//2))\n    allowed=size<=low and cap>minimum and True and target>=high\n    capacity=target if allowed else cap\n    version=epoch+allowed\n    free=capacity-size\n    return [capacity,allowed,version,free,low,high,pins]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([16,3,4,4,7,0,N]), {1: [8, True, 2, 5, 4, 7, 0], 2: [8, True, 3, 5, 4, 7, 0], 3: [8, True, 4, 5, 4, 7, 0], 4: [8, True, 5, 5, 4, 7, 0], 5: [8, True, 6, 5, 4, 7, 0]}[N])\ncheck('1', solve([16,4,4,4,8,0,N]), {1: [8, True, 2, 4, 4, 8, 0], 2: [8, True, 3, 4, 4, 8, 0], 3: [8, True, 4, 4, 4, 8, 0], 4: [8, True, 5, 4, 4, 8, 0], 5: [8, True, 6, 4, 4, 8, 0]}[N])\ncheck('2', solve([16,3,4,4,9,0,N]), {1: [16, False, 1, 13, 4, 9, 0], 2: [16, False, 2, 13, 4, 9, 0], 3: [16, False, 3, 13, 4, 9, 0], 4: [16, False, 4, 13, 4, 9, 0], 5: [16, False, 5, 13, 4, 9, 0]}[N])\ncheck('3', solve([16,3,4,4,7,1,N]), {1: [16, False, 1, 13, 4, 7, 1], 2: [16, False, 2, 13, 4, 7, 1], 3: [16, False, 3, 13, 4, 7, 1], 4: [16, False, 4, 13, 4, 7, 1], 5: [16, False, 5, 13, 4, 7, 1]}[N])\ncheck('4', solve([4,1,4,2,2,0,N]), {1: [4, False, 1, 3, 2, 2, 0], 2: [4, False, 2, 3, 2, 2, 0], 3: [4, False, 3, 3, 2, 2, 0], 4: [4, False, 4, 3, 2, 2, 0], 5: [4, False, 5, 3, 2, 2, 0]}[N])\ncheck('5', solve([12,7,4,8,6,0,N]), {1: [7, True, 2, 0, 8, 6, 0], 2: [7, True, 3, 0, 8, 6, 0], 3: [7, True, 4, 0, 8, 6, 0], 4: [7, True, 5, 0, 8, 6, 0], 5: [7, True, 6, 0, 8, 6, 0]}[N])\ncheck('6', solve([12,2,8,3,7,0,N]), {1: [8, True, 2, 6, 3, 7, 0], 2: [8, True, 3, 6, 3, 7, 0], 3: [8, True, 4, 6, 3, 7, 0], 4: [8, True, 5, 6, 3, 7, 0], 5: [8, True, 6, 6, 3, 7, 0]}[N])\ncheck('7', solve([16,5,4,4,6,0,N]), {1: [16, False, 1, 11, 4, 6, 0], 2: [16, False, 2, 11, 4, 6, 0], 3: [16, False, 3, 11, 4, 6, 0], 4: [16, False, 4, 11, 4, 6, 0], 5: [16, False, 5, 11, 4, 6, 0]}[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"},"fixed":{"sha256":"c62e80d93b4e73aede69140174f127703762da34f36904ccee3ba0505734b7ca","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    cap,size,minimum,low,high,pins,epoch=x\n    target=max(minimum,max(size,cap//2))\n    allowed=size<=low and cap>minimum and not pins and target>=high\n    capacity=target if allowed else cap\n    version=epoch+allowed\n    free=capacity-size\n    return [capacity,allowed,version,free,low,high,pins]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('0', solve([16,3,4,4,7,0,N]), {1: [8, True, 2, 5, 4, 7, 0], 2: [8, True, 3, 5, 4, 7, 0], 3: [8, True, 4, 5, 4, 7, 0], 4: [8, True, 5, 5, 4, 7, 0], 5: [8, True, 6, 5, 4, 7, 0]}[N])\ncheck('1', solve([16,4,4,4,8,0,N]), {1: [8, True, 2, 4, 4, 8, 0], 2: [8, True, 3, 4, 4, 8, 0], 3: [8, True, 4, 4, 4, 8, 0], 4: [8, True, 5, 4, 4, 8, 0], 5: [8, True, 6, 4, 4, 8, 0]}[N])\ncheck('2', solve([16,3,4,4,9,0,N]), {1: [16, False, 1, 13, 4, 9, 0], 2: [16, False, 2, 13, 4, 9, 0], 3: [16, False, 3, 13, 4, 9, 0], 4: [16, False, 4, 13, 4, 9, 0], 5: [16, False, 5, 13, 4, 9, 0]}[N])\ncheck('3', solve([16,3,4,4,7,1,N]), {1: [16, False, 1, 13, 4, 7, 1], 2: [16, False, 2, 13, 4, 7, 1], 3: [16, False, 3, 13, 4, 7, 1], 4: [16, False, 4, 13, 4, 7, 1], 5: [16, False, 5, 13, 4, 7, 1]}[N])\ncheck('4', solve([4,1,4,2,2,0,N]), {1: [4, False, 1, 3, 2, 2, 0], 2: [4, False, 2, 3, 2, 2, 0], 3: [4, False, 3, 3, 2, 2, 0], 4: [4, False, 4, 3, 2, 2, 0], 5: [4, False, 5, 3, 2, 2, 0]}[N])\ncheck('5', solve([12,7,4,8,6,0,N]), {1: [7, True, 2, 0, 8, 6, 0], 2: [7, True, 3, 0, 8, 6, 0], 3: [7, True, 4, 0, 8, 6, 0], 4: [7, True, 5, 0, 8, 6, 0], 5: [7, True, 6, 0, 8, 6, 0]}[N])\ncheck('6', solve([12,2,8,3,7,0,N]), {1: [8, True, 2, 6, 3, 7, 0], 2: [8, True, 3, 6, 3, 7, 0], 3: [8, True, 4, 6, 3, 7, 0], 4: [8, True, 5, 6, 3, 7, 0], 5: [8, True, 6, 6, 3, 7, 0]}[N])\ncheck('7', solve([16,5,4,4,6,0,N]), {1: [16, False, 1, 11, 4, 6, 0], 2: [16, False, 2, 11, 4, 6, 0], 3: [16, False, 3, 11, 4, 6, 0], 4: [16, False, 4, 11, 4, 6, 0], 5: [16, False, 5, 11, 4, 6, 0]}[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-shrink-hysteresis-pin-barrier","generated_at":"2026-09-29T14:44:38.742518+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 pin barrier invariant in shrink-hysteresis.","root_cause":"Deque shrink reallocates while a storage borrow exists.","sha256":"be10b8b121f8eede31061bf5cddcb962ac8970da3412af9b7c4a55c09965e172","title":"Deque shrink reallocates while a storage borrow exists · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":43.773,"exit_code":1,"observations":[{"actual":[8,true,2,5,4,7,0],"check":"0","expected":[8,true,2,5,4,7,0],"passed":true},{"actual":[8,true,2,4,4,8,0],"check":"1","expected":[8,true,2,4,4,8,0],"passed":true},{"actual":[16,false,1,13,4,9,0],"check":"2","expected":[16,false,1,13,4,9,0],"passed":true},{"actual":[8,true,2,5,4,7,1],"check":"3","expected":[16,false,1,13,4,7,1],"passed":false},{"actual":[4,false,1,3,2,2,0],"check":"4","expected":[4,false,1,3,2,2,0],"passed":true},{"actual":[7,true,2,0,8,6,0],"check":"5","expected":[7,true,2,0,8,6,0],"passed":true},{"actual":[8,true,2,6,3,7,0],"check":"6","expected":[8,true,2,6,3,7,0],"passed":true},{"actual":[16,false,1,11,4,6,0],"check":"7","expected":[16,false,1,11,4,6,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [8, true, 2, 5, 4, 7, 0], \"expected\": [8, true, 2, 5, 4, 7, 0], \"passed\": true}, {\"check\": \"1\", \"actual\": [8, true, 2, 4, 4, 8, 0], \"expected\": [8, true, 2, 4, 4, 8, 0], \"passed\": true}, {\"check\": \"2\", \"actual\": [16, false, 1, 13, 4, 9, 0], \"expected\": [16, false, 1, 13, 4, 9, 0], \"passed\": true}, {\"check\": \"3\", \"actual\": [8, true, 2, 5, 4, 7, 1], \"expected\": [16, false, 1, 13, 4, 7, 1], \"passed\": false}, {\"check\": \"4\", \"actual\": [4, false, 1, 3, 2, 2, 0], \"expected\": [4, false, 1, 3, 2, 2, 0], \"passed\": true}, {\"check\": \"5\", \"actual\": [7, true, 2, 0, 8, 6, 0], \"expected\": [7, true, 2, 0, 8, 6, 0], \"passed\": true}, {\"check\": \"6\", \"actual\": [8, true, 2, 6, 3, 7, 0], \"expected\": [8, true, 2, 6, 3, 7, 0], \"passed\": true}, {\"check\": \"7\", \"actual\": [16, false, 1, 11, 4, 6, 0], \"expected\": [16, false, 1, 11, 4, 6, 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.313,"exit_code":1,"observations":[{"actual":[8,true,2,5,4,7,0],"check":"0","expected":[8,true,2,5,4,7,0],"passed":true},{"actual":[8,true,2,4,4,8,0],"check":"1","expected":[8,true,2,4,4,8,0],"passed":true},{"actual":[16,false,1,13,4,9,0],"check":"2","expected":[16,false,1,13,4,9,0],"passed":true},{"actual":[8,true,2,5,4,7,1],"check":"3","expected":[16,false,1,13,4,7,1],"passed":false},{"actual":[4,false,1,3,2,2,0],"check":"4","expected":[4,false,1,3,2,2,0],"passed":true},{"actual":[7,true,2,0,8,6,0],"check":"5","expected":[7,true,2,0,8,6,0],"passed":true},{"actual":[8,true,2,6,3,7,0],"check":"6","expected":[8,true,2,6,3,7,0],"passed":true},{"actual":[16,false,1,11,4,6,0],"check":"7","expected":[16,false,1,11,4,6,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [8, true, 2, 5, 4, 7, 0], \"expected\": [8, true, 2, 5, 4, 7, 0], \"passed\": true}, {\"check\": \"1\", \"actual\": [8, true, 2, 4, 4, 8, 0], \"expected\": [8, true, 2, 4, 4, 8, 0], \"passed\": true}, {\"check\": \"2\", \"actual\": [16, false, 1, 13, 4, 9, 0], \"expected\": [16, false, 1, 13, 4, 9, 0], \"passed\": true}, {\"check\": \"3\", \"actual\": [8, true, 2, 5, 4, 7, 1], \"expected\": [16, false, 1, 13, 4, 7, 1], \"passed\": false}, {\"check\": \"4\", \"actual\": [4, false, 1, 3, 2, 2, 0], \"expected\": [4, false, 1, 3, 2, 2, 0], \"passed\": true}, {\"check\": \"5\", \"actual\": [7, true, 2, 0, 8, 6, 0], \"expected\": [7, true, 2, 0, 8, 6, 0], \"passed\": true}, {\"check\": \"6\", \"actual\": [8, true, 2, 6, 3, 7, 0], \"expected\": [8, true, 2, 6, 3, 7, 0], \"passed\": true}, {\"check\": \"7\", \"actual\": [16, false, 1, 11, 4, 6, 0], \"expected\": [16, false, 1, 11, 4, 6, 0], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.859,"exit_code":0,"observations":[{"actual":[8,true,2,5,4,7,0],"check":"0","expected":[8,true,2,5,4,7,0],"passed":true},{"actual":[8,true,2,4,4,8,0],"check":"1","expected":[8,true,2,4,4,8,0],"passed":true},{"actual":[16,false,1,13,4,9,0],"check":"2","expected":[16,false,1,13,4,9,0],"passed":true},{"actual":[16,false,1,13,4,7,1],"check":"3","expected":[16,false,1,13,4,7,1],"passed":true},{"actual":[4,false,1,3,2,2,0],"check":"4","expected":[4,false,1,3,2,2,0],"passed":true},{"actual":[7,true,2,0,8,6,0],"check":"5","expected":[7,true,2,0,8,6,0],"passed":true},{"actual":[8,true,2,6,3,7,0],"check":"6","expected":[8,true,2,6,3,7,0],"passed":true},{"actual":[16,false,1,11,4,6,0],"check":"7","expected":[16,false,1,11,4,6,0],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"0\", \"actual\": [8, true, 2, 5, 4, 7, 0], \"expected\": [8, true, 2, 5, 4, 7, 0], \"passed\": true}, {\"check\": \"1\", \"actual\": [8, true, 2, 4, 4, 8, 0], \"expected\": [8, true, 2, 4, 4, 8, 0], \"passed\": true}, {\"check\": \"2\", \"actual\": [16, false, 1, 13, 4, 9, 0], \"expected\": [16, false, 1, 13, 4, 9, 0], \"passed\": true}, {\"check\": \"3\", \"actual\": [16, false, 1, 13, 4, 7, 1], \"expected\": [16, false, 1, 13, 4, 7, 1], \"passed\": true}, {\"check\": \"4\", \"actual\": [4, false, 1, 3, 2, 2, 0], \"expected\": [4, false, 1, 3, 2, 2, 0], \"passed\": true}, {\"check\": \"5\", \"actual\": [7, true, 2, 0, 8, 6, 0], \"expected\": [7, true, 2, 0, 8, 6, 0], \"passed\": true}, {\"check\": \"6\", \"actual\": [8, true, 2, 6, 3, 7, 0], \"expected\": [8, true, 2, 6, 3, 7, 0], \"passed\": true}, {\"check\": \"7\", \"actual\": [16, false, 1, 11, 4, 6, 0], \"expected\": [16, false, 1, 11, 4, 6, 0], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}