{"abstract":"H applied to |+i> stays at y = +1 instead of moving to y = -1.","category":"Quantum circuit simulation","checks":7,"contract":"Input [[x, y, z], channels] (decimal strings). Apply in order: depol p (r -> (1-p) r), dephase p (x, y scaled by 1-2p), bitflip p (y, z scaled by 1-2p), ampdamp g (x, y scaled by sqrt(1-g), z -> g + (1-g) z toward |0> at z=+1), h ((x,y,z) -> (z,-y,x)), s ((x,y) -> (-y,x)), x ((y,z) -> (-y,-z)). Return the final vector rounded to 6 decimals.","evaluation_group":"w2-quantum_circuit_simulation-bloch-noise-channels","failed_approach":"The attempted repair negates all three coordinates after swapping, a point reflection rather than a rotation.","family":"w2-quantum_circuit_simulation-bloch-noise-channels-hadamard-y-reflection","id":"FA-91261","implementations":{"attempt":{"sha256":"e3b10c4c3a1069a5e6085533edb40b5322332068bce409e3cd8034f1a7ff5935","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(x):\n    bx, by, bz = [float(v) for v in x[0]]\n    for ch in x[1]:\n        kind = ch[0]\n        if kind == 'depol':\n            p = float(ch[1])\n            bx, by, bz = (1 - p) * bx, (1 - p) * by, (1 - p) * bz\n        elif kind == 'dephase':\n            p = float(ch[1])\n            bx, by = (1 - 2 * p) * bx, (1 - 2 * p) * by\n        elif kind == 'bitflip':\n            p = float(ch[1])\n            by, bz = (1 - 2 * p) * by, (1 - 2 * p) * bz\n        elif kind == 'ampdamp':\n            g = float(ch[1])\n            s = math.sqrt(1 - g)\n            bx, by, bz = s * bx, s * by, g + (1 - g) * bz\n        elif kind == 'h':\n            bx, by, bz = -bz, -by, -bx\n        elif kind == 's':\n            bx, by = -by, bx\n        elif kind == 'x':\n            by, bz = -by, -bz\n    return [round(v, 6) + 0.0 for v in (bx, by, bz)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression: hadamard on y', [['0', '1', '0'], [['h']]], [0.0, -1.0, 0.0]], ['regression: random channel chain 1', [['0.2317', '0.4662', '-0.3393'], [['h'], ['ampdamp', '0.1'], ['h'], ['h']]], [-0.321888, -0.442276, 0.30853]], ['regression: random channel chain 5', [['-0.4729', '-0.0797', '-0.3692'], [['h'], ['s'], ['dephase', '0.1']]], [-0.06376, -0.29536, -0.4729]], ['control: amplitude damping from |1>', [['0', '0', '-1'], [['ampdamp', '0.5']]], [0.0, 0.0, 0.0]], ['control: dephasing plus state', [['1', '0', '0'], [['dephase', '0.25']]], [0.5, 0.0, 0.0]], ['control: bit flip on |0>', [['0', '0', '1'], [['bitflip', '0.25']]], [0.0, 0.0, 0.5]], ['control: s on x', [['1', '0', '0'], [['s']]], [0.0, 1.0, 0.0]]], [['regression: random channel chain 8', [['0.255', '-0.4128', '-0.2664'], [['x'], ['dephase', '0.05'], ['h'], ['depol', '0.05']]], [0.25308, -0.352944, 0.218025]], ['regression: random channel chain 10', [['0.0325', '0.65', '0.2184'], [['depol', '0.2'], ['ampdamp', '0.05'], ['bitflip', '0.05'], ['h']]], [0.194386, -0.45615, 0.025342]], ['regression: random channel chain 13', [['-0.3842', '-0.4838', '0.2088'], [['h'], ['depol', '0.05']]], [0.19836, 0.45961, -0.36499]], ['control: x on |+i>', [['0', '1', '0'], [['x']]], [0.0, -1.0, 0.0]], ['control: depolarize', [['0.6', '0', '0.8'], [['depol', '0.1']]], [0.54, 0.0, 0.72]], ['control: random channel chain 0', [['0.0691', '-0.4004', '0.0791'], [['dephase', '0.2'], ['bitflip', '0.3'], ['s']]], [0.096096, 0.04146, 0.03164]], ['control: random channel chain 2', [['0.0766', '-0.6718', '0.0357'], [['s']]], [0.6718, 0.0766, 0.0357]]], [['regression: random channel chain 14', [['-0.1159', '-0.3227', '0.1975'], [['bitflip', '0.3'], ['h'], ['bitflip', '0.1'], ['dephase', '0.3']]], [0.0316, 0.041306, -0.09272]], ['regression: random channel chain 16', [['0.0125', '-0.322', '0.0664'], [['h'], ['ampdamp', '0.05']]], [0.064719, 0.313847, 0.061875]], ['regression: random channel chain 13', [['-0.3842', '-0.4838', '0.2088'], [['h'], ['depol', '0.05']]], [0.19836, 0.45961, -0.36499]], ['control: random channel chain 3', [['0.2389', '-0.1722', '0.2639'], [['dephase', '0.1'], ['bitflip', '0.2'], ['x']]], [0.19112, 0.082656, -0.15834]], ['control: random channel chain 4', [['-0.0477', '-0.2431', '-0.2391'], [['x'], ['depol', '0.5'], ['x'], ['bitflip', '0.1']]], [-0.02385, -0.09724, -0.09564]], ['control: random channel chain 6', [['0.394', '0.1792', '-0.6952'], [['x']]], [0.394, -0.1792, 0.6952]], ['control: random channel chain 7', [['0.2531', '-0.7095', '0.5685'], [['ampdamp', '0.2'], ['bitflip', '0.1'], ['dephase', '0.2'], ['x']]], [0.135828, 0.304606, -0.52384]]], [['regression: random channel chain 33', [['-0.1736', '-0.2281', '-0.3032'], [['ampdamp', '0.1'], ['h']]], [-0.17288, 0.216395, -0.164691]], ['regression: random channel chain 38', [['0.1646', '-0.3434', '-0.0118'], [['s'], ['h']]], [-0.0118, -0.1646, 0.3434]], ['regression: random channel chain 16', [['0.0125', '-0.322', '0.0664'], [['h'], ['ampdamp', '0.05']]], [0.064719, 0.313847, 0.061875]], ['control: random channel chain 9', [['0.2932', '0.3716', '-0.2949'], [['x'], ['bitflip', '0.2'], ['ampdamp', '0.3']]], [0.245309, -0.186542, 0.423858]], ['control: random channel chain 11', [['0.2608', '0.1361', '-0.2576'], [['x'], ['depol', '0.05']]], [0.24776, -0.129295, 0.24472]], ['control: random channel chain 12', [['0.3838', '0.2434', '0.1995'], [['x'], ['s'], ['depol', '0.5'], ['dephase', '0.05']]], [0.10953, 0.17271, -0.09975]], ['control: random channel chain 15', [['0.2915', '0.4987', '-0.2812'], [['ampdamp', '0.1'], ['s'], ['x']]], [-0.473108, -0.276541, 0.15308]]], [['regression: hadamard on y', [['0', '1', '0'], [['h']]], [0.0, -1.0, 0.0]], ['regression: random channel chain 1', [['0.2317', '0.4662', '-0.3393'], [['h'], ['ampdamp', '0.1'], ['h'], ['h']]], [-0.321888, -0.442276, 0.30853]], ['regression: random channel chain 28', [['-0.4727', '0.0368', '-0.4788'], [['h'], ['ampdamp', '0.2']]], [-0.428252, -0.032915, -0.17816]], ['control: random channel chain 17', [['0.1445', '-0.5422', '-0.0485'], [['s'], ['s'], ['dephase', '0.2'], ['dephase', '0.05']]], [-0.07803, 0.292788, -0.0485]], ['control: random channel chain 18', [['-0.3894', '0.6131', '-0.5953'], [['bitflip', '0.05']]], [-0.3894, 0.55179, -0.53577]], ['control: random channel chain 19', [['0.6907', '-0.2493', '0.6355'], [['depol', '0.5'], ['dephase', '0.05'], ['depol', '0.05']]], [0.295274, -0.106576, 0.301862]], ['control: random channel chain 20', [['0.1424', '0.3599', '0.436'], [['dephase', '0.3'], ['depol', '0.5']]], [0.02848, 0.07198, 0.218]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\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":"acc190eb8fa047d2bbea7fddc4605067eab4279c431bf0473edab018d0d30b96","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(x):\n    bx, by, bz = [float(v) for v in x[0]]\n    for ch in x[1]:\n        kind = ch[0]\n        if kind == 'depol':\n            p = float(ch[1])\n            bx, by, bz = (1 - p) * bx, (1 - p) * by, (1 - p) * bz\n        elif kind == 'dephase':\n            p = float(ch[1])\n            bx, by = (1 - 2 * p) * bx, (1 - 2 * p) * by\n        elif kind == 'bitflip':\n            p = float(ch[1])\n            by, bz = (1 - 2 * p) * by, (1 - 2 * p) * bz\n        elif kind == 'ampdamp':\n            g = float(ch[1])\n            s = math.sqrt(1 - g)\n            bx, by, bz = s * bx, s * by, g + (1 - g) * bz\n        elif kind == 'h':\n            bx, by, bz = bz, by, bx\n        elif kind == 's':\n            bx, by = -by, bx\n        elif kind == 'x':\n            by, bz = -by, -bz\n    return [round(v, 6) + 0.0 for v in (bx, by, bz)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression: hadamard on y', [['0', '1', '0'], [['h']]], [0.0, -1.0, 0.0]], ['regression: random channel chain 1', [['0.2317', '0.4662', '-0.3393'], [['h'], ['ampdamp', '0.1'], ['h'], ['h']]], [-0.321888, -0.442276, 0.30853]], ['regression: random channel chain 5', [['-0.4729', '-0.0797', '-0.3692'], [['h'], ['s'], ['dephase', '0.1']]], [-0.06376, -0.29536, -0.4729]], ['control: amplitude damping from |1>', [['0', '0', '-1'], [['ampdamp', '0.5']]], [0.0, 0.0, 0.0]], ['control: dephasing plus state', [['1', '0', '0'], [['dephase', '0.25']]], [0.5, 0.0, 0.0]], ['control: bit flip on |0>', [['0', '0', '1'], [['bitflip', '0.25']]], [0.0, 0.0, 0.5]], ['control: s on x', [['1', '0', '0'], [['s']]], [0.0, 1.0, 0.0]]], [['regression: random channel chain 8', [['0.255', '-0.4128', '-0.2664'], [['x'], ['dephase', '0.05'], ['h'], ['depol', '0.05']]], [0.25308, -0.352944, 0.218025]], ['regression: random channel chain 10', [['0.0325', '0.65', '0.2184'], [['depol', '0.2'], ['ampdamp', '0.05'], ['bitflip', '0.05'], ['h']]], [0.194386, -0.45615, 0.025342]], ['regression: random channel chain 13', [['-0.3842', '-0.4838', '0.2088'], [['h'], ['depol', '0.05']]], [0.19836, 0.45961, -0.36499]], ['control: x on |+i>', [['0', '1', '0'], [['x']]], [0.0, -1.0, 0.0]], ['control: depolarize', [['0.6', '0', '0.8'], [['depol', '0.1']]], [0.54, 0.0, 0.72]], ['control: random channel chain 0', [['0.0691', '-0.4004', '0.0791'], [['dephase', '0.2'], ['bitflip', '0.3'], ['s']]], [0.096096, 0.04146, 0.03164]], ['control: random channel chain 2', [['0.0766', '-0.6718', '0.0357'], [['s']]], [0.6718, 0.0766, 0.0357]]], [['regression: random channel chain 14', [['-0.1159', '-0.3227', '0.1975'], [['bitflip', '0.3'], ['h'], ['bitflip', '0.1'], ['dephase', '0.3']]], [0.0316, 0.041306, -0.09272]], ['regression: random channel chain 16', [['0.0125', '-0.322', '0.0664'], [['h'], ['ampdamp', '0.05']]], [0.064719, 0.313847, 0.061875]], ['regression: random channel chain 13', [['-0.3842', '-0.4838', '0.2088'], [['h'], ['depol', '0.05']]], [0.19836, 0.45961, -0.36499]], ['control: random channel chain 3', [['0.2389', '-0.1722', '0.2639'], [['dephase', '0.1'], ['bitflip', '0.2'], ['x']]], [0.19112, 0.082656, -0.15834]], ['control: random channel chain 4', [['-0.0477', '-0.2431', '-0.2391'], [['x'], ['depol', '0.5'], ['x'], ['bitflip', '0.1']]], [-0.02385, -0.09724, -0.09564]], ['control: random channel chain 6', [['0.394', '0.1792', '-0.6952'], [['x']]], [0.394, -0.1792, 0.6952]], ['control: random channel chain 7', [['0.2531', '-0.7095', '0.5685'], [['ampdamp', '0.2'], ['bitflip', '0.1'], ['dephase', '0.2'], ['x']]], [0.135828, 0.304606, -0.52384]]], [['regression: random channel chain 33', [['-0.1736', '-0.2281', '-0.3032'], [['ampdamp', '0.1'], ['h']]], [-0.17288, 0.216395, -0.164691]], ['regression: random channel chain 38', [['0.1646', '-0.3434', '-0.0118'], [['s'], ['h']]], [-0.0118, -0.1646, 0.3434]], ['regression: random channel chain 16', [['0.0125', '-0.322', '0.0664'], [['h'], ['ampdamp', '0.05']]], [0.064719, 0.313847, 0.061875]], ['control: random channel chain 9', [['0.2932', '0.3716', '-0.2949'], [['x'], ['bitflip', '0.2'], ['ampdamp', '0.3']]], [0.245309, -0.186542, 0.423858]], ['control: random channel chain 11', [['0.2608', '0.1361', '-0.2576'], [['x'], ['depol', '0.05']]], [0.24776, -0.129295, 0.24472]], ['control: random channel chain 12', [['0.3838', '0.2434', '0.1995'], [['x'], ['s'], ['depol', '0.5'], ['dephase', '0.05']]], [0.10953, 0.17271, -0.09975]], ['control: random channel chain 15', [['0.2915', '0.4987', '-0.2812'], [['ampdamp', '0.1'], ['s'], ['x']]], [-0.473108, -0.276541, 0.15308]]], [['regression: hadamard on y', [['0', '1', '0'], [['h']]], [0.0, -1.0, 0.0]], ['regression: random channel chain 1', [['0.2317', '0.4662', '-0.3393'], [['h'], ['ampdamp', '0.1'], ['h'], ['h']]], [-0.321888, -0.442276, 0.30853]], ['regression: random channel chain 28', [['-0.4727', '0.0368', '-0.4788'], [['h'], ['ampdamp', '0.2']]], [-0.428252, -0.032915, -0.17816]], ['control: random channel chain 17', [['0.1445', '-0.5422', '-0.0485'], [['s'], ['s'], ['dephase', '0.2'], ['dephase', '0.05']]], [-0.07803, 0.292788, -0.0485]], ['control: random channel chain 18', [['-0.3894', '0.6131', '-0.5953'], [['bitflip', '0.05']]], [-0.3894, 0.55179, -0.53577]], ['control: random channel chain 19', [['0.6907', '-0.2493', '0.6355'], [['depol', '0.5'], ['dephase', '0.05'], ['depol', '0.05']]], [0.295274, -0.106576, 0.301862]], ['control: random channel chain 20', [['0.1424', '0.3599', '0.436'], [['dephase', '0.3'], ['depol', '0.5']]], [0.02848, 0.07198, 0.218]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\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":"4b5e6730ce8c857092727a9e6537d1ad1aea4ca1b3e01b36cb540136ca71e7a4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(x):\n    bx, by, bz = [float(v) for v in x[0]]\n    for ch in x[1]:\n        kind = ch[0]\n        if kind == 'depol':\n            p = float(ch[1])\n            bx, by, bz = (1 - p) * bx, (1 - p) * by, (1 - p) * bz\n        elif kind == 'dephase':\n            p = float(ch[1])\n            bx, by = (1 - 2 * p) * bx, (1 - 2 * p) * by\n        elif kind == 'bitflip':\n            p = float(ch[1])\n            by, bz = (1 - 2 * p) * by, (1 - 2 * p) * bz\n        elif kind == 'ampdamp':\n            g = float(ch[1])\n            s = math.sqrt(1 - g)\n            bx, by, bz = s * bx, s * by, g + (1 - g) * bz\n        elif kind == 'h':\n            bx, by, bz = bz, -by, bx\n        elif kind == 's':\n            bx, by = -by, bx\n        elif kind == 'x':\n            by, bz = -by, -bz\n    return [round(v, 6) + 0.0 for v in (bx, by, bz)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression: hadamard on y', [['0', '1', '0'], [['h']]], [0.0, -1.0, 0.0]], ['regression: random channel chain 1', [['0.2317', '0.4662', '-0.3393'], [['h'], ['ampdamp', '0.1'], ['h'], ['h']]], [-0.321888, -0.442276, 0.30853]], ['regression: random channel chain 5', [['-0.4729', '-0.0797', '-0.3692'], [['h'], ['s'], ['dephase', '0.1']]], [-0.06376, -0.29536, -0.4729]], ['control: amplitude damping from |1>', [['0', '0', '-1'], [['ampdamp', '0.5']]], [0.0, 0.0, 0.0]], ['control: dephasing plus state', [['1', '0', '0'], [['dephase', '0.25']]], [0.5, 0.0, 0.0]], ['control: bit flip on |0>', [['0', '0', '1'], [['bitflip', '0.25']]], [0.0, 0.0, 0.5]], ['control: s on x', [['1', '0', '0'], [['s']]], [0.0, 1.0, 0.0]]], [['regression: random channel chain 8', [['0.255', '-0.4128', '-0.2664'], [['x'], ['dephase', '0.05'], ['h'], ['depol', '0.05']]], [0.25308, -0.352944, 0.218025]], ['regression: random channel chain 10', [['0.0325', '0.65', '0.2184'], [['depol', '0.2'], ['ampdamp', '0.05'], ['bitflip', '0.05'], ['h']]], [0.194386, -0.45615, 0.025342]], ['regression: random channel chain 13', [['-0.3842', '-0.4838', '0.2088'], [['h'], ['depol', '0.05']]], [0.19836, 0.45961, -0.36499]], ['control: x on |+i>', [['0', '1', '0'], [['x']]], [0.0, -1.0, 0.0]], ['control: depolarize', [['0.6', '0', '0.8'], [['depol', '0.1']]], [0.54, 0.0, 0.72]], ['control: random channel chain 0', [['0.0691', '-0.4004', '0.0791'], [['dephase', '0.2'], ['bitflip', '0.3'], ['s']]], [0.096096, 0.04146, 0.03164]], ['control: random channel chain 2', [['0.0766', '-0.6718', '0.0357'], [['s']]], [0.6718, 0.0766, 0.0357]]], [['regression: random channel chain 14', [['-0.1159', '-0.3227', '0.1975'], [['bitflip', '0.3'], ['h'], ['bitflip', '0.1'], ['dephase', '0.3']]], [0.0316, 0.041306, -0.09272]], ['regression: random channel chain 16', [['0.0125', '-0.322', '0.0664'], [['h'], ['ampdamp', '0.05']]], [0.064719, 0.313847, 0.061875]], ['regression: random channel chain 13', [['-0.3842', '-0.4838', '0.2088'], [['h'], ['depol', '0.05']]], [0.19836, 0.45961, -0.36499]], ['control: random channel chain 3', [['0.2389', '-0.1722', '0.2639'], [['dephase', '0.1'], ['bitflip', '0.2'], ['x']]], [0.19112, 0.082656, -0.15834]], ['control: random channel chain 4', [['-0.0477', '-0.2431', '-0.2391'], [['x'], ['depol', '0.5'], ['x'], ['bitflip', '0.1']]], [-0.02385, -0.09724, -0.09564]], ['control: random channel chain 6', [['0.394', '0.1792', '-0.6952'], [['x']]], [0.394, -0.1792, 0.6952]], ['control: random channel chain 7', [['0.2531', '-0.7095', '0.5685'], [['ampdamp', '0.2'], ['bitflip', '0.1'], ['dephase', '0.2'], ['x']]], [0.135828, 0.304606, -0.52384]]], [['regression: random channel chain 33', [['-0.1736', '-0.2281', '-0.3032'], [['ampdamp', '0.1'], ['h']]], [-0.17288, 0.216395, -0.164691]], ['regression: random channel chain 38', [['0.1646', '-0.3434', '-0.0118'], [['s'], ['h']]], [-0.0118, -0.1646, 0.3434]], ['regression: random channel chain 16', [['0.0125', '-0.322', '0.0664'], [['h'], ['ampdamp', '0.05']]], [0.064719, 0.313847, 0.061875]], ['control: random channel chain 9', [['0.2932', '0.3716', '-0.2949'], [['x'], ['bitflip', '0.2'], ['ampdamp', '0.3']]], [0.245309, -0.186542, 0.423858]], ['control: random channel chain 11', [['0.2608', '0.1361', '-0.2576'], [['x'], ['depol', '0.05']]], [0.24776, -0.129295, 0.24472]], ['control: random channel chain 12', [['0.3838', '0.2434', '0.1995'], [['x'], ['s'], ['depol', '0.5'], ['dephase', '0.05']]], [0.10953, 0.17271, -0.09975]], ['control: random channel chain 15', [['0.2915', '0.4987', '-0.2812'], [['ampdamp', '0.1'], ['s'], ['x']]], [-0.473108, -0.276541, 0.15308]]], [['regression: hadamard on y', [['0', '1', '0'], [['h']]], [0.0, -1.0, 0.0]], ['regression: random channel chain 1', [['0.2317', '0.4662', '-0.3393'], [['h'], ['ampdamp', '0.1'], ['h'], ['h']]], [-0.321888, -0.442276, 0.30853]], ['regression: random channel chain 28', [['-0.4727', '0.0368', '-0.4788'], [['h'], ['ampdamp', '0.2']]], [-0.428252, -0.032915, -0.17816]], ['control: random channel chain 17', [['0.1445', '-0.5422', '-0.0485'], [['s'], ['s'], ['dephase', '0.2'], ['dephase', '0.05']]], [-0.07803, 0.292788, -0.0485]], ['control: random channel chain 18', [['-0.3894', '0.6131', '-0.5953'], [['bitflip', '0.05']]], [-0.3894, 0.55179, -0.53577]], ['control: random channel chain 19', [['0.6907', '-0.2493', '0.6355'], [['depol', '0.5'], ['dephase', '0.05'], ['depol', '0.05']]], [0.295274, -0.106576, 0.301862]], ['control: random channel chain 20', [['0.1424', '0.3599', '0.436'], [['dephase', '0.3'], ['depol', '0.5']]], [0.02848, 0.07198, 0.218]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\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":"A deterministic bounded teaching model with a stipulated toy contract; amplitudes are rounded to fixed decimals for strict JSON output. It is not a production quantum SDK and claims no standards conformance. 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":"w2-quantum_circuit_simulation-bloch-noise-channels-hadamard-y-reflection","generated_at":"2026-09-29T14:51:34.315013+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Single-qubit noise channels on the Bloch ball are the standard sanity model for T1/T2 behaviour; axis or scale slips mislead calibration.","repair":"Use (x, y, z) -> (z, -y, x).","root_cause":"The Hadamard map swaps x and z but does not negate y.","sha256":"21e357122ec6f46e9e0d617e340a18002f36f1c07c5ae279598d2226340d990e","title":"Bloch Hadamard leaves y unchanged · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.133,"exit_code":1,"observations":[{"actual":[0.0,-1.0,0.0],"check":"regression: hadamard on y","expected":[0.0,-1.0,0.0],"passed":true},{"actual":[0.321888,-0.442276,-0.10853],"check":"regression: random channel chain 1","expected":[-0.321888,-0.442276,0.30853],"passed":false},{"actual":[-0.06376,0.29536,0.4729],"check":"regression: random channel chain 5","expected":[-0.06376,-0.29536,-0.4729],"passed":false},{"actual":[0.0,0.0,0.0],"check":"control: amplitude damping from |1>","expected":[0.0,0.0,0.0],"passed":true},{"actual":[0.5,0.0,0.0],"check":"control: dephasing plus state","expected":[0.5,0.0,0.0],"passed":true},{"actual":[0.0,0.0,0.5],"check":"control: bit flip on |0>","expected":[0.0,0.0,0.5],"passed":true},{"actual":[0.0,1.0,0.0],"check":"control: s on x","expected":[0.0,1.0,0.0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: hadamard on y\", \"actual\": [0.0, -1.0, 0.0], \"expected\": [0.0, -1.0, 0.0], \"passed\": true}, {\"check\": \"regression: random channel chain 1\", \"actual\": [0.321888, -0.442276, -0.10853], \"expected\": [-0.321888, -0.442276, 0.30853], \"passed\": false}, {\"check\": \"regression: random channel chain 5\", \"actual\": [-0.06376, 0.29536, 0.4729], \"expected\": [-0.06376, -0.29536, -0.4729], \"passed\": false}, {\"check\": \"control: amplitude damping from |1>\", \"actual\": [0.0, 0.0, 0.0], \"expected\": [0.0, 0.0, 0.0], \"passed\": true}, {\"check\": \"control: dephasing plus state\", \"actual\": [0.5, 0.0, 0.0], \"expected\": [0.5, 0.0, 0.0], \"passed\": true}, {\"check\": \"control: bit flip on |0>\", \"actual\": [0.0, 0.0, 0.5], \"expected\": [0.0, 0.0, 0.5], \"passed\": true}, {\"check\": \"control: s on x\", \"actual\": [0.0, 1.0, 0.0], \"expected\": [0.0, 1.0, 0.0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.58,"exit_code":1,"observations":[{"actual":[0.0,1.0,0.0],"check":"regression: hadamard on y","expected":[0.0,-1.0,0.0],"passed":false},{"actual":[-0.321888,0.442276,0.30853],"check":"regression: random channel chain 1","expected":[-0.321888,-0.442276,0.30853],"passed":false},{"actual":[0.06376,-0.29536,-0.4729],"check":"regression: random channel chain 5","expected":[-0.06376,-0.29536,-0.4729],"passed":false},{"actual":[0.0,0.0,0.0],"check":"control: amplitude damping from |1>","expected":[0.0,0.0,0.0],"passed":true},{"actual":[0.5,0.0,0.0],"check":"control: dephasing plus state","expected":[0.5,0.0,0.0],"passed":true},{"actual":[0.0,0.0,0.5],"check":"control: bit flip on |0>","expected":[0.0,0.0,0.5],"passed":true},{"actual":[0.0,1.0,0.0],"check":"control: s on x","expected":[0.0,1.0,0.0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: hadamard on y\", \"actual\": [0.0, 1.0, 0.0], \"expected\": [0.0, -1.0, 0.0], \"passed\": false}, {\"check\": \"regression: random channel chain 1\", \"actual\": [-0.321888, 0.442276, 0.30853], \"expected\": [-0.321888, -0.442276, 0.30853], \"passed\": false}, {\"check\": \"regression: random channel chain 5\", \"actual\": [0.06376, -0.29536, -0.4729], \"expected\": [-0.06376, -0.29536, -0.4729], \"passed\": false}, {\"check\": \"control: amplitude damping from |1>\", \"actual\": [0.0, 0.0, 0.0], \"expected\": [0.0, 0.0, 0.0], \"passed\": true}, {\"check\": \"control: dephasing plus state\", \"actual\": [0.5, 0.0, 0.0], \"expected\": [0.5, 0.0, 0.0], \"passed\": true}, {\"check\": \"control: bit flip on |0>\", \"actual\": [0.0, 0.0, 0.5], \"expected\": [0.0, 0.0, 0.5], \"passed\": true}, {\"check\": \"control: s on x\", \"actual\": [0.0, 1.0, 0.0], \"expected\": [0.0, 1.0, 0.0], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.988,"exit_code":0,"observations":[{"actual":[0.0,-1.0,0.0],"check":"regression: hadamard on y","expected":[0.0,-1.0,0.0],"passed":true},{"actual":[-0.321888,-0.442276,0.30853],"check":"regression: random channel chain 1","expected":[-0.321888,-0.442276,0.30853],"passed":true},{"actual":[-0.06376,-0.29536,-0.4729],"check":"regression: random channel chain 5","expected":[-0.06376,-0.29536,-0.4729],"passed":true},{"actual":[0.0,0.0,0.0],"check":"control: amplitude damping from |1>","expected":[0.0,0.0,0.0],"passed":true},{"actual":[0.5,0.0,0.0],"check":"control: dephasing plus state","expected":[0.5,0.0,0.0],"passed":true},{"actual":[0.0,0.0,0.5],"check":"control: bit flip on |0>","expected":[0.0,0.0,0.5],"passed":true},{"actual":[0.0,1.0,0.0],"check":"control: s on x","expected":[0.0,1.0,0.0],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: hadamard on y\", \"actual\": [0.0, -1.0, 0.0], \"expected\": [0.0, -1.0, 0.0], \"passed\": true}, {\"check\": \"regression: random channel chain 1\", \"actual\": [-0.321888, -0.442276, 0.30853], \"expected\": [-0.321888, -0.442276, 0.30853], \"passed\": true}, {\"check\": \"regression: random channel chain 5\", \"actual\": [-0.06376, -0.29536, -0.4729], \"expected\": [-0.06376, -0.29536, -0.4729], \"passed\": true}, {\"check\": \"control: amplitude damping from |1>\", \"actual\": [0.0, 0.0, 0.0], \"expected\": [0.0, 0.0, 0.0], \"passed\": true}, {\"check\": \"control: dephasing plus state\", \"actual\": [0.5, 0.0, 0.0], \"expected\": [0.5, 0.0, 0.0], \"passed\": true}, {\"check\": \"control: bit flip on |0>\", \"actual\": [0.0, 0.0, 0.5], \"expected\": [0.0, 0.0, 0.5], \"passed\": true}, {\"check\": \"control: s on x\", \"actual\": [0.0, 1.0, 0.0], \"expected\": [0.0, 1.0, 0.0], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}