{"abstract":"Copying rows leaves row and column axes unchanged.","category":"Linear algebra","checks":4,"contract":"Integer matrix/vector entries, rectangular rows, compatible multiplication dimensions, and square matrices for determinant, trace, inverse, symmetry and characteristic-polynomial operations. Rational matrix outputs are reduced Fraction strings. Matrix transpose rectangular. Exact operational definition: [list(row) for row in zip(*m)]","contract_signature":"m","evaluation_group":"model-bf86bc51c2d8172b","failed_approach":"Reversing the transposed rows adds an unwanted reflection.","family":"xn-matrix-transpose-rectangular","id":"FA-6026","implementations":{"attempt":{"sha256":"541d47d7cf45161fd0a2bd65a8e8c9e1bbc4572418d47c09b774e0a3e7a67a3a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nimport calendar\nimport statistics\nimport itertools\nfrom fractions import Fraction\nfrom datetime import date, datetime, timedelta, timezone\nfrom decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR\n\nN = 1\nobservations = []\ndef solve(m):\n    return [list(row) for row in zip(*m)][::-1]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([[1, 2, 3], [4, 5, 6]],)', solve(*([[1, 2, 3], [4, 5, 6]],)), [[1, 4], [2, 5], [3, 6]])\ncheck('fixture 2: ([[1], [2]],)', solve(*([[1], [2]],)), [[1, 2]])\ncheck('fixture 3: ([[7]],)', solve(*([[7]],)), [[7]])\ncheck('fixture 4: ([],)', 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":"a9323c241760e5feaf19015d3a4ca9b278b267acad6715426d6eaf80f28f7297","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nimport calendar\nimport statistics\nimport itertools\nfrom fractions import Fraction\nfrom datetime import date, datetime, timedelta, timezone\nfrom decimal import Decimal, ROUND_HALF_UP, ROUND_DOWN, ROUND_CEILING, ROUND_FLOOR\n\nN = 1\nobservations = []\ndef solve(m):\n    return [row[:] for row in m]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1: ([[1, 2, 3], [4, 5, 6]],)', solve(*([[1, 2, 3], [4, 5, 6]],)), [[1, 4], [2, 5], [3, 6]])\ncheck('fixture 2: ([[1], [2]],)', solve(*([[1], [2]],)), [[1, 2]])\ncheck('fixture 3: ([[7]],)', solve(*([[7]],)), [[7]])\ncheck('fixture 4: ([],)', 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":" 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":"xn-matrix-transpose-rectangular","generated_at":"2026-09-29T14:37:56.540641+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Small exact fixtures expose this error without platform timing, external services, or probabilistic observations. Linear algebra results depend on the stated convention.","root_cause":"Copying rows leaves row and column axes unchanged.","sha256":"366211593fb239ba6ad2c3bc82a452e513a1596de591d2b54223d0df5620b9fc","title":"Matrix transpose rectangular · 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":49.53,"exit_code":1,"observations":[{"actual":[[3,6],[2,5],[1,4]],"check":"fixture 1: ([[1, 2, 3], [4, 5, 6]],)","expected":[[1,4],[2,5],[3,6]],"passed":false},{"actual":[[1,2]],"check":"fixture 2: ([[1], [2]],)","expected":[[1,2]],"passed":true},{"actual":[[7]],"check":"fixture 3: ([[7]],)","expected":[[7]],"passed":true},{"actual":[],"check":"fixture 4: ([],)","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([[1, 2, 3], [4, 5, 6]],)\", \"actual\": [[3, 6], [2, 5], [1, 4]], \"expected\": [[1, 4], [2, 5], [3, 6]], \"passed\": false}, {\"check\": \"fixture 2: ([[1], [2]],)\", \"actual\": [[1, 2]], \"expected\": [[1, 2]], \"passed\": true}, {\"check\": \"fixture 3: ([[7]],)\", \"actual\": [[7]], \"expected\": [[7]], \"passed\": true}, {\"check\": \"fixture 4: ([],)\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":51.593,"exit_code":1,"observations":[{"actual":[[1,2,3],[4,5,6]],"check":"fixture 1: ([[1, 2, 3], [4, 5, 6]],)","expected":[[1,4],[2,5],[3,6]],"passed":false},{"actual":[[1],[2]],"check":"fixture 2: ([[1], [2]],)","expected":[[1,2]],"passed":false},{"actual":[[7]],"check":"fixture 3: ([[7]],)","expected":[[7]],"passed":true},{"actual":[],"check":"fixture 4: ([],)","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1: ([[1, 2, 3], [4, 5, 6]],)\", \"actual\": [[1, 2, 3], [4, 5, 6]], \"expected\": [[1, 4], [2, 5], [3, 6]], \"passed\": false}, {\"check\": \"fixture 2: ([[1], [2]],)\", \"actual\": [[1], [2]], \"expected\": [[1, 2]], \"passed\": false}, {\"check\": \"fixture 3: ([[7]],)\", \"actual\": [[7]], \"expected\": [[7]], \"passed\": true}, {\"check\": \"fixture 4: ([],)\", \"actual\": [], \"expected\": [], \"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."}}