{"abstract":"Explicit isotope labels disappear from atom keys.","category":"Molecular graph representation","checks":6,"contract":"Return [element, isotope] exactly; None means unspecified and integer zero means an explicit model sentinel.","evaluation_group":"model-9a0ad2fe9a3b863e","failed_approach":"A truthiness fallback conflates explicit zero sentinel with absent isotope.","family":"z-chemical_graphs-isotope","id":"FA-12441","implementations":{"attempt":{"sha256":"cfa26602dbe21250520d37f66dba765f9111fe4793c37cc900106b65dd8755ab","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(element, isotope):\n    return [element, isotope or None]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('varying isotope', solve('C', 12+N), ['C',12+N])\ncheck('unspecified', solve('C', None), ['C',None])\ncheck('zero sentinel', solve('X', 0), ['X',0])\ncheck('hydrogen isotope', solve('H', 2), ['H',2])\ncheck('different element', solve('N', 15), ['N',15])\ncheck('large label', solve('X', 100+N), ['X',100+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":"2d8d5694b428fd26906d2f0bb8ece0e6bab775bc8f7e08a4df69a378f99c0f4d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(element, isotope):\n    return [element, None]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('varying isotope', solve('C', 12+N), ['C',12+N])\ncheck('unspecified', solve('C', None), ['C',None])\ncheck('zero sentinel', solve('X', 0), ['X',0])\ncheck('hydrogen isotope', solve('H', 2), ['H',2])\ncheck('different element', solve('N', 15), ['N',15])\ncheck('large label', solve('X', 100+N), ['X',100+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":"2dbeb106376b34bd35e0233ce0db8db8fa3134917bf155e84a3a2ea93faa4b10","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(element, isotope):\n    return [element, isotope]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('varying isotope', solve('C', 12+N), ['C',12+N])\ncheck('unspecified', solve('C', None), ['C',None])\ncheck('zero sentinel', solve('X', 0), ['X',0])\ncheck('hydrogen isotope', solve('H', 2), ['H',2])\ncheck('different element', solve('N', 15), ['N',15])\ncheck('large label', solve('X', 100+N), ['X',100+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":"Toy representation only; no valence inference, chemical sanitization, synthesis, or real molecular identity determination. 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-chemical_graphs-isotope","generated_at":"2026-09-29T14:38:56.853672+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Controlled molecular graph interchange model; tests isolate atom or bond representation errors without claiming chemical validity or production toolkit equivalence.","repair":"Implement the explicit toy representation contract: Return [element, isotope] exactly; None means unspecified and integer zero means an explicit model sentinel.","root_cause":"Element-only keys erase explicit isotope tags.","sha256":"0e8dacc663417a2ef1629766895bd2f5a79db28e668cdb6ad94955b137b92c34","title":"Explicit isotope labels disappear from atom keys · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.212,"exit_code":1,"observations":[{"actual":["C",13],"check":"varying isotope","expected":["C",13],"passed":true},{"actual":["C",null],"check":"unspecified","expected":["C",null],"passed":true},{"actual":["X",null],"check":"zero sentinel","expected":["X",0],"passed":false},{"actual":["H",2],"check":"hydrogen isotope","expected":["H",2],"passed":true},{"actual":["N",15],"check":"different element","expected":["N",15],"passed":true},{"actual":["X",101],"check":"large label","expected":["X",101],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"varying isotope\", \"actual\": [\"C\", 13], \"expected\": [\"C\", 13], \"passed\": true}, {\"check\": \"unspecified\", \"actual\": [\"C\", null], \"expected\": [\"C\", null], \"passed\": true}, {\"check\": \"zero sentinel\", \"actual\": [\"X\", null], \"expected\": [\"X\", 0], \"passed\": false}, {\"check\": \"hydrogen isotope\", \"actual\": [\"H\", 2], \"expected\": [\"H\", 2], \"passed\": true}, {\"check\": \"different element\", \"actual\": [\"N\", 15], \"expected\": [\"N\", 15], \"passed\": true}, {\"check\": \"large label\", \"actual\": [\"X\", 101], \"expected\": [\"X\", 101], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.917,"exit_code":1,"observations":[{"actual":["C",null],"check":"varying isotope","expected":["C",13],"passed":false},{"actual":["C",null],"check":"unspecified","expected":["C",null],"passed":true},{"actual":["X",null],"check":"zero sentinel","expected":["X",0],"passed":false},{"actual":["H",null],"check":"hydrogen isotope","expected":["H",2],"passed":false},{"actual":["N",null],"check":"different element","expected":["N",15],"passed":false},{"actual":["X",null],"check":"large label","expected":["X",101],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"varying isotope\", \"actual\": [\"C\", null], \"expected\": [\"C\", 13], \"passed\": false}, {\"check\": \"unspecified\", \"actual\": [\"C\", null], \"expected\": [\"C\", null], \"passed\": true}, {\"check\": \"zero sentinel\", \"actual\": [\"X\", null], \"expected\": [\"X\", 0], \"passed\": false}, {\"check\": \"hydrogen isotope\", \"actual\": [\"H\", null], \"expected\": [\"H\", 2], \"passed\": false}, {\"check\": \"different element\", \"actual\": [\"N\", null], \"expected\": [\"N\", 15], \"passed\": false}, {\"check\": \"large label\", \"actual\": [\"X\", null], \"expected\": [\"X\", 101], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":42.016,"exit_code":0,"observations":[{"actual":["C",13],"check":"varying isotope","expected":["C",13],"passed":true},{"actual":["C",null],"check":"unspecified","expected":["C",null],"passed":true},{"actual":["X",0],"check":"zero sentinel","expected":["X",0],"passed":true},{"actual":["H",2],"check":"hydrogen isotope","expected":["H",2],"passed":true},{"actual":["N",15],"check":"different element","expected":["N",15],"passed":true},{"actual":["X",101],"check":"large label","expected":["X",101],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"varying isotope\", \"actual\": [\"C\", 13], \"expected\": [\"C\", 13], \"passed\": true}, {\"check\": \"unspecified\", \"actual\": [\"C\", null], \"expected\": [\"C\", null], \"passed\": true}, {\"check\": \"zero sentinel\", \"actual\": [\"X\", 0], \"expected\": [\"X\", 0], \"passed\": true}, {\"check\": \"hydrogen isotope\", \"actual\": [\"H\", 2], \"expected\": [\"H\", 2], \"passed\": true}, {\"check\": \"different element\", \"actual\": [\"N\", 15], \"expected\": [\"N\", 15], \"passed\": true}, {\"check\": \"large label\", \"actual\": [\"X\", 101], \"expected\": [\"X\", 101], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}