{"abstract":"The operation returns a result or retained state that violates this contract: Emit all ordered pairs in left-major, right-minor order, retaining duplicates.","category":"Collection algebra","checks":4,"contract":"Emit all ordered pairs in left-major, right-minor order, retaining duplicates. Inputs are the finite Python values shown by the executable fixtures; no concurrent execution is assumed.","contract_signature":"x, y=None","evaluation_group":"model-ff3195c5090de74c","failed_approach":"Position-wise zipping does not enumerate every pair.","family":"xr-cartesian-product-order","id":"FA-4266","implementations":{"attempt":{"sha256":"c0fb05cc033ed0c1d47fddbf8688898cac1248d74d82a13001d43eb16d658fcf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x, y=None):\n    return [[a,b] for a,b in zip(x,y)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('both empty', solve([], []), [])\ncheck('empty right operand', solve(['a'], []), [])\ncheck('empty left operand', solve([], ['b']), [])\ncheck('overlap and multiplicity', solve(['b', 'a', 'b'], ['b', 'c', 'c']), [['b', 'b'], ['b', 'c'], ['b', 'c'], ['a', 'b'], ['a', 'c'], ['a', 'c'], ['b', 'b'], ['b', 'c'], ['b', 'c']])\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":"e604369870e63bd6b23f66d8b6ca4af0fb08ee223ec9aeb8456600d7cab630bf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x, y=None):\n    return [[a,b] for b in y for a in x]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('both empty', solve([], []), [])\ncheck('empty right operand', solve(['a'], []), [])\ncheck('empty left operand', solve([], ['b']), [])\ncheck('overlap and multiplicity', solve(['b', 'a', 'b'], ['b', 'c', 'c']), [['b', 'b'], ['b', 'c'], ['b', 'c'], ['a', 'b'], ['a', 'c'], ['a', 'c'], ['b', 'b'], ['b', 'c'], ['b', 'c']])\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":"xr-cartesian-product-order","generated_at":"2026-09-29T14:37:37.379418+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A controlled local-runtime regression for collection APIs, language semantics, or ownership wrappers. Fixtures include boundary and interaction cases.","root_cause":"Loop nesting changes the required left-major product order.","sha256":"a4b27c3931ccd93313d6bfb96bc02d7deaf9a92860fb007f8b91f970bee43093","title":"Cartesian product order · case 01","variant":1,"variant_policy":"Five execution reruns of a fixed adversarial fixture suite; variant number does not alter semantic inputs.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":37.347,"exit_code":1,"observations":[{"actual":[],"check":"both empty","expected":[],"passed":true},{"actual":[],"check":"empty right operand","expected":[],"passed":true},{"actual":[],"check":"empty left operand","expected":[],"passed":true},{"actual":[["b","b"],["a","c"],["b","c"]],"check":"overlap and multiplicity","expected":[["b","b"],["b","c"],["b","c"],["a","b"],["a","c"],["a","c"],["b","b"],["b","c"],["b","c"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"both empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty right operand\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty left operand\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"overlap and multiplicity\", \"actual\": [[\"b\", \"b\"], [\"a\", \"c\"], [\"b\", \"c\"]], \"expected\": [[\"b\", \"b\"], [\"b\", \"c\"], [\"b\", \"c\"], [\"a\", \"b\"], [\"a\", \"c\"], [\"a\", \"c\"], [\"b\", \"b\"], [\"b\", \"c\"], [\"b\", \"c\"]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.871,"exit_code":1,"observations":[{"actual":[],"check":"both empty","expected":[],"passed":true},{"actual":[],"check":"empty right operand","expected":[],"passed":true},{"actual":[],"check":"empty left operand","expected":[],"passed":true},{"actual":[["b","b"],["a","b"],["b","b"],["b","c"],["a","c"],["b","c"],["b","c"],["a","c"],["b","c"]],"check":"overlap and multiplicity","expected":[["b","b"],["b","c"],["b","c"],["a","b"],["a","c"],["a","c"],["b","b"],["b","c"],["b","c"]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"both empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty right operand\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"empty left operand\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"overlap and multiplicity\", \"actual\": [[\"b\", \"b\"], [\"a\", \"b\"], [\"b\", \"b\"], [\"b\", \"c\"], [\"a\", \"c\"], [\"b\", \"c\"], [\"b\", \"c\"], [\"a\", \"c\"], [\"b\", \"c\"]], \"expected\": [[\"b\", \"b\"], [\"b\", \"c\"], [\"b\", \"c\"], [\"a\", \"b\"], [\"a\", \"c\"], [\"a\", \"c\"], [\"b\", \"b\"], [\"b\", \"c\"], [\"b\", \"c\"]], \"passed\": false}], \"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."}}