{"abstract":"pair generation favors one orientation.","category":"Preference pair construction","checks":6,"contract":"Rows are [chosen,rejected,weight]. Return each row and its mirrored orientation, each with half its input weight, preserving row order.","contract_signature":"rows","evaluation_group":"preference-balanced-direction","failed_approach":"Mirroring text but copying the full original weight doubles total sample mass.","family":"w3-preference-pair-construction-balanced-direction","id":"FA-100116","implementations":{"attempt":{"sha256":"a77a90c801b6917a4e36fc5539f613b9223a20d8364a92f26f03031d3e36ff55","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows):\n    return [[r[0],r[1],r[2]] for r in rows for _ in (0,1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('single mirrored pair',solve([['a','b',N]]),[['a','b',[N,2]],['b','a',[N,2]]])\ncheck('two rows preserve order',solve([['a','b',2],['c','d',4]]),[['a','b',[2,2]],['b','a',[2,2]],['c','d',[4,2]],['d','c',[4,2]]])\ncheck('empty',solve([]),[])\ncheck('weight zero',solve([['a','b',0]]),[['a','b',[0,2]],['b','a',[0,2]]])\ncheck('odd weight exact',solve([['a','b',3]]),[['a','b',[3,2]],['b','a',[3,2]]])\ncheck('same labels',solve([['x','x',N]]),[['x','x',[N,2]],['x','x',[N,2]]])\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":"2dbec0c302774b4e1ea729ce1d0ffb54733267314b10e0b5bc218938c89ef9b1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(rows):\n    return [[r[0],r[1],r[2]] for r in rows]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('single mirrored pair',solve([['a','b',N]]),[['a','b',[N,2]],['b','a',[N,2]]])\ncheck('two rows preserve order',solve([['a','b',2],['c','d',4]]),[['a','b',[2,2]],['b','a',[2,2]],['c','d',[4,2]],['d','c',[4,2]]])\ncheck('empty',solve([]),[])\ncheck('weight zero',solve([['a','b',0]]),[['a','b',[0,2]],['b','a',[0,2]]])\ncheck('odd weight exact',solve([['a','b',3]]),[['a','b',[3,2]],['b','a',[3,2]]])\ncheck('same labels',solve([['x','x',N]]),[['x','x',[N,2]],['x','x',[N,2]]])\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":"These are explicit toy record contracts; they do not claim compatibility with a trainer or improved model behavior. 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":"w3-preference-pair-construction-balanced-direction","generated_at":"2026-09-30T16:48:31.747774+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small deterministic preference-data transform makes pair semantics inspectable without a training framework.","root_cause":"Pair generation keeps only one arbitrary input ordering, biasing the dataset toward one side.","sha256":"f50da525e257dcb0db3c820f2a60d938d960592c8368516f1913c4dd388465ba","title":"Preference pairs: pair generation favors one orientation · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":28.596,"exit_code":1,"observations":[{"actual":[["a","b",1],["a","b",1]],"check":"single mirrored pair","expected":[["a","b",[1,2]],["b","a",[1,2]]],"passed":false},{"actual":[["a","b",2],["a","b",2],["c","d",4],["c","d",4]],"check":"two rows preserve order","expected":[["a","b",[2,2]],["b","a",[2,2]],["c","d",[4,2]],["d","c",[4,2]]],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[["a","b",0],["a","b",0]],"check":"weight zero","expected":[["a","b",[0,2]],["b","a",[0,2]]],"passed":false},{"actual":[["a","b",3],["a","b",3]],"check":"odd weight exact","expected":[["a","b",[3,2]],["b","a",[3,2]]],"passed":false},{"actual":[["x","x",1],["x","x",1]],"check":"same labels","expected":[["x","x",[1,2]],["x","x",[1,2]]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"single mirrored pair\", \"actual\": [[\"a\", \"b\", 1], [\"a\", \"b\", 1]], \"expected\": [[\"a\", \"b\", [1, 2]], [\"b\", \"a\", [1, 2]]], \"passed\": false}, {\"check\": \"two rows preserve order\", \"actual\": [[\"a\", \"b\", 2], [\"a\", \"b\", 2], [\"c\", \"d\", 4], [\"c\", \"d\", 4]], \"expected\": [[\"a\", \"b\", [2, 2]], [\"b\", \"a\", [2, 2]], [\"c\", \"d\", [4, 2]], [\"d\", \"c\", [4, 2]]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"weight zero\", \"actual\": [[\"a\", \"b\", 0], [\"a\", \"b\", 0]], \"expected\": [[\"a\", \"b\", [0, 2]], [\"b\", \"a\", [0, 2]]], \"passed\": false}, {\"check\": \"odd weight exact\", \"actual\": [[\"a\", \"b\", 3], [\"a\", \"b\", 3]], \"expected\": [[\"a\", \"b\", [3, 2]], [\"b\", \"a\", [3, 2]]], \"passed\": false}, {\"check\": \"same labels\", \"actual\": [[\"x\", \"x\", 1], [\"x\", \"x\", 1]], \"expected\": [[\"x\", \"x\", [1, 2]], [\"x\", \"x\", [1, 2]]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":26.318,"exit_code":1,"observations":[{"actual":[["a","b",1]],"check":"single mirrored pair","expected":[["a","b",[1,2]],["b","a",[1,2]]],"passed":false},{"actual":[["a","b",2],["c","d",4]],"check":"two rows preserve order","expected":[["a","b",[2,2]],["b","a",[2,2]],["c","d",[4,2]],["d","c",[4,2]]],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[["a","b",0]],"check":"weight zero","expected":[["a","b",[0,2]],["b","a",[0,2]]],"passed":false},{"actual":[["a","b",3]],"check":"odd weight exact","expected":[["a","b",[3,2]],["b","a",[3,2]]],"passed":false},{"actual":[["x","x",1]],"check":"same labels","expected":[["x","x",[1,2]],["x","x",[1,2]]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"single mirrored pair\", \"actual\": [[\"a\", \"b\", 1]], \"expected\": [[\"a\", \"b\", [1, 2]], [\"b\", \"a\", [1, 2]]], \"passed\": false}, {\"check\": \"two rows preserve order\", \"actual\": [[\"a\", \"b\", 2], [\"c\", \"d\", 4]], \"expected\": [[\"a\", \"b\", [2, 2]], [\"b\", \"a\", [2, 2]], [\"c\", \"d\", [4, 2]], [\"d\", \"c\", [4, 2]]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"weight zero\", \"actual\": [[\"a\", \"b\", 0]], \"expected\": [[\"a\", \"b\", [0, 2]], [\"b\", \"a\", [0, 2]]], \"passed\": false}, {\"check\": \"odd weight exact\", \"actual\": [[\"a\", \"b\", 3]], \"expected\": [[\"a\", \"b\", [3, 2]], [\"b\", \"a\", [3, 2]]], \"passed\": false}, {\"check\": \"same labels\", \"actual\": [[\"x\", \"x\", 1]], \"expected\": [[\"x\", \"x\", [1, 2]], [\"x\", \"x\", [1, 2]]], \"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."}}