{"abstract":"Dictionary clear codes retain stale learned phrases.","category":"Compression format semantics","checks":6,"contract":"Toy dictionary starts with {0:a,1:b}. Tokens [put,k,text] add phrases; [clear] restores exactly the literals; [get,k] emits the mapped phrase or ?.","evaluation_group":"model-9309e1e7c338d153","failed_approach":"Clearing every entry also loses the permanent literal alphabet.","family":"z-compression-dictionary-clear","id":"FA-11601","implementations":{"attempt":{"sha256":"a96f22495752f611db6b9dc5da50a09876929ce477721646b79bebb2df4c887e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(tokens):\n    d={0:'a',1:'b'}; out=[]\n    for t in tokens:\n        if t[0]=='put': d[t[1]]=t[2]\n        elif t[0]=='clear': d={}\n        else: out.append(d.get(t[1],'?'))\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('epoch invalidates phrase',solve([['put',2,'a'*N],['clear'],['get',2]]),['?'])\ncheck('literal survives',solve([['clear'],['get',0]]),['a'])\ncheck('phrase before clear',solve([['put',2,'ab'],['get',2]]),['ab'])\ncheck('reassignment after clear',solve([['put',2,'ab'],['clear'],['put',2,'ba'],['get',2]]),['ba'])\ncheck('repeated clears',solve([['clear'],['clear'],['get',1]]),['b'])\ncheck('empty',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":"ae7fb88ba2a1946e05c0e42b75d4661307e6209ad6fd61033d795e34e364c75c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(tokens):\n    d={0:'a',1:'b'}; out=[]\n    for t in tokens:\n        if t[0]=='put': d[t[1]]=t[2]\n        elif t[0]=='get': out.append(d.get(t[1],'?'))\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('epoch invalidates phrase',solve([['put',2,'a'*N],['clear'],['get',2]]),['?'])\ncheck('literal survives',solve([['clear'],['get',0]]),['a'])\ncheck('phrase before clear',solve([['put',2,'ab'],['get',2]]),['ab'])\ncheck('reassignment after clear',solve([['put',2,'ab'],['clear'],['put',2,'ba'],['get',2]]),['ba'])\ncheck('repeated clears',solve([['clear'],['clear'],['get',1]]),['b'])\ncheck('empty',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"},"fixed":{"sha256":"3e25c661f2dfbaae0e9d940aaa84ac9fb6af356b783e866861a381dea0160897","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(tokens):\n    d={0:'a',1:'b'}; out=[]\n    for t in tokens:\n        if t[0]=='put': d[t[1]]=t[2]\n        elif t[0]=='clear': d={0:'a',1:'b'}\n        else: out.append(d.get(t[1],'?'))\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('epoch invalidates phrase',solve([['put',2,'a'*N],['clear'],['get',2]]),['?'])\ncheck('literal survives',solve([['clear'],['get',0]]),['a'])\ncheck('phrase before clear',solve([['put',2,'ab'],['get',2]]),['ab'])\ncheck('reassignment after clear',solve([['put',2,'ab'],['clear'],['put',2,'ba'],['get',2]]),['ba'])\ncheck('repeated clears',solve([['clear'],['clear'],['get',1]]),['b'])\ncheck('empty',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":"Controlled educational model, not a complete implementation of a production compression format. 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":"z-compression-dictionary-clear","generated_at":"2026-09-29T14:38:49.299700+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small offline codec model isolates a compression-specific failure without external files or libraries.","repair":"Replace learned dictionary state with a fresh literal dictionary on every clear marker.","root_cause":"A clear marker is ignored, retaining phrases from the preceding dictionary epoch.","sha256":"241a6cc0657a331dc7e960efb7c5ce812a4020bb0151bee74e24686b0c0d296e","title":"Dictionary clear codes retain stale learned phrases · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.746,"exit_code":1,"observations":[{"actual":["?"],"check":"epoch invalidates phrase","expected":["?"],"passed":true},{"actual":["?"],"check":"literal survives","expected":["a"],"passed":false},{"actual":["ab"],"check":"phrase before clear","expected":["ab"],"passed":true},{"actual":["ba"],"check":"reassignment after clear","expected":["ba"],"passed":true},{"actual":["?"],"check":"repeated clears","expected":["b"],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"epoch invalidates phrase\", \"actual\": [\"?\"], \"expected\": [\"?\"], \"passed\": true}, {\"check\": \"literal survives\", \"actual\": [\"?\"], \"expected\": [\"a\"], \"passed\": false}, {\"check\": \"phrase before clear\", \"actual\": [\"ab\"], \"expected\": [\"ab\"], \"passed\": true}, {\"check\": \"reassignment after clear\", \"actual\": [\"ba\"], \"expected\": [\"ba\"], \"passed\": true}, {\"check\": \"repeated clears\", \"actual\": [\"?\"], \"expected\": [\"b\"], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.837,"exit_code":1,"observations":[{"actual":["a"],"check":"epoch invalidates phrase","expected":["?"],"passed":false},{"actual":["a"],"check":"literal survives","expected":["a"],"passed":true},{"actual":["ab"],"check":"phrase before clear","expected":["ab"],"passed":true},{"actual":["ba"],"check":"reassignment after clear","expected":["ba"],"passed":true},{"actual":["b"],"check":"repeated clears","expected":["b"],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"epoch invalidates phrase\", \"actual\": [\"a\"], \"expected\": [\"?\"], \"passed\": false}, {\"check\": \"literal survives\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"phrase before clear\", \"actual\": [\"ab\"], \"expected\": [\"ab\"], \"passed\": true}, {\"check\": \"reassignment after clear\", \"actual\": [\"ba\"], \"expected\": [\"ba\"], \"passed\": true}, {\"check\": \"repeated clears\", \"actual\": [\"b\"], \"expected\": [\"b\"], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.865,"exit_code":0,"observations":[{"actual":["?"],"check":"epoch invalidates phrase","expected":["?"],"passed":true},{"actual":["a"],"check":"literal survives","expected":["a"],"passed":true},{"actual":["ab"],"check":"phrase before clear","expected":["ab"],"passed":true},{"actual":["ba"],"check":"reassignment after clear","expected":["ba"],"passed":true},{"actual":["b"],"check":"repeated clears","expected":["b"],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"epoch invalidates phrase\", \"actual\": [\"?\"], \"expected\": [\"?\"], \"passed\": true}, {\"check\": \"literal survives\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"phrase before clear\", \"actual\": [\"ab\"], \"expected\": [\"ab\"], \"passed\": true}, {\"check\": \"reassignment after clear\", \"actual\": [\"ba\"], \"expected\": [\"ba\"], \"passed\": true}, {\"check\": \"repeated clears\", \"actual\": [\"b\"], \"expected\": [\"b\"], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}