{"abstract":"Constant propagation retains a fact after an unknown assignment.","category":"Compiler transformation correctness","checks":6,"contract":"Interpret assignment facts (name, kind, value); const sets a known integer, input and call invalidate that name. Return final known facts.","contract_signature":"ops","evaluation_group":"model-648fea7a18ec7e84","failed_approach":"Clearing only for calls leaves input assignments stale.","family":"z-compilers-constant-kill","id":"FA-11441","implementations":{"attempt":{"sha256":"0325543e67e8768731d87dca152291f4760bade0ba107a4e9d7f82eaadf9b511","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ops):\n    env = {}\n    for name, kind, value in ops:\n        if kind == 'const': env[name] = value\n        elif kind == 'call': env.pop(name, None)\n    return env\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('empty block', solve([]), {})\ncheck('constant assignment', solve([('x','const',N)]), {'x':N})\ncheck('input kills constant', solve([('x','const',N),('x','input',None)]), {})\ncheck('call kills constant', solve([('x','const',N),('x','call',None)]), {})\ncheck('unrelated fact survives', solve([('x','const',N),('y','input',None)]), {'x':N})\ncheck('constant restored', solve([('x','input',None),('x','const',N+1)]), {'x':N+1})\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":"231321cfa58e9136dbdc601431296a555280716d22d6c873eecd7923963f9892","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ops):\n    env = {}\n    for name, kind, value in ops:\n        if kind == 'const': env[name] = value\n    return env\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('empty block', solve([]), {})\ncheck('constant assignment', solve([('x','const',N)]), {'x':N})\ncheck('input kills constant', solve([('x','const',N),('x','input',None)]), {})\ncheck('call kills constant', solve([('x','const',N),('x','call',None)]), {})\ncheck('unrelated fact survives', solve([('x','const',N),('y','input',None)]), {'x':N})\ncheck('constant restored', solve([('x','input',None),('x','const',N+1)]), {'x':N+1})\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":" 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-compilers-constant-kill","generated_at":"2026-09-29T14:38:47.990659+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic miniature compiler-pass model; inputs are explicit IR facts, not a production compiler.","root_cause":"An unknown write is omitted from the environment transfer function.","sha256":"76d929ef7a1d25490221c1169c08fb3423b1ac3a5663f4f90ac057530bcd4643","title":"Constant propagation retains a fact after an unknown assignment · 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":37.283,"exit_code":1,"observations":[{"actual":{},"check":"empty block","expected":{},"passed":true},{"actual":{"x":1},"check":"constant assignment","expected":{"x":1},"passed":true},{"actual":{"x":1},"check":"input kills constant","expected":{},"passed":false},{"actual":{},"check":"call kills constant","expected":{},"passed":true},{"actual":{"x":1},"check":"unrelated fact survives","expected":{"x":1},"passed":true},{"actual":{"x":2},"check":"constant restored","expected":{"x":2},"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"empty block\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"constant assignment\", \"actual\": {\"x\": 1}, \"expected\": {\"x\": 1}, \"passed\": true}, {\"check\": \"input kills constant\", \"actual\": {\"x\": 1}, \"expected\": {}, \"passed\": false}, {\"check\": \"call kills constant\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"unrelated fact survives\", \"actual\": {\"x\": 1}, \"expected\": {\"x\": 1}, \"passed\": true}, {\"check\": \"constant restored\", \"actual\": {\"x\": 2}, \"expected\": {\"x\": 2}, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.915,"exit_code":1,"observations":[{"actual":{},"check":"empty block","expected":{},"passed":true},{"actual":{"x":1},"check":"constant assignment","expected":{"x":1},"passed":true},{"actual":{"x":1},"check":"input kills constant","expected":{},"passed":false},{"actual":{"x":1},"check":"call kills constant","expected":{},"passed":false},{"actual":{"x":1},"check":"unrelated fact survives","expected":{"x":1},"passed":true},{"actual":{"x":2},"check":"constant restored","expected":{"x":2},"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"empty block\", \"actual\": {}, \"expected\": {}, \"passed\": true}, {\"check\": \"constant assignment\", \"actual\": {\"x\": 1}, \"expected\": {\"x\": 1}, \"passed\": true}, {\"check\": \"input kills constant\", \"actual\": {\"x\": 1}, \"expected\": {}, \"passed\": false}, {\"check\": \"call kills constant\", \"actual\": {\"x\": 1}, \"expected\": {}, \"passed\": false}, {\"check\": \"unrelated fact survives\", \"actual\": {\"x\": 1}, \"expected\": {\"x\": 1}, \"passed\": true}, {\"check\": \"constant restored\", \"actual\": {\"x\": 2}, \"expected\": {\"x\": 2}, \"passed\": true}], \"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."}}