{"abstract":"Grading from 14 to 16 uses the large increment though the step starts below the break.","category":"Knitting and sewing pattern grading","checks":8,"contract":"Sizes 6..22 in steps of 2 (others -> \"error: size\"). Grading one size step between sizes s and s+2 changes the circumference by `small` cm if the lower size s < brk, else `large`. Going down subtracts the same step amounts. Return [circumference, per quarter-panel = circumference/4], both half-up to 0.1.","contract_signature":"base_size, target_size, base_cm, small, large, brk","evaluation_group":"w2-knitting_and_sewing_pattern_grading-grade-rules","failed_approach":"Using the start size is right going up but wrong going down.","family":"w2-knitting_and_sewing_pattern_grading-grade-rules-step-interval-size","id":"FA-97516","implementations":{"attempt":{"sha256":"40aaa3a81327074c2028d13d4c46b52d0b32931f141d9d8e416b5e5c6e5f063d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(base_size, target_size, base_cm, small, large, brk):\n    SIZES = [6, 8, 10, 12, 14, 16, 18, 20, 22]\n    if base_size not in SIZES or target_size not in SIZES:\n        return 'error: size'\n    i, j = SIZES.index(base_size), SIZES.index(target_size)\n    m = Fraction(str(base_cm))\n    step = 1 if j > i else -1\n    k = i\n    while k != j:\n        lo = k\n        inc = small if SIZES[lo] < brk else large\n        m += step * inc\n        k += step\n    q = m / 4\n    return [math.floor(m * 10 + Fraction(1, 2)) / 10, math.floor(q * 10 + Fraction(1, 2)) / 10]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['regression: step interval size', [10, 20, '92.5', 4, 6, 16], [116.5, 29.1]],\n  ['repair check: step interval size', [20, 8, '92.5', 4, 7, 16], [62.5, 15.6]],\n  ['generated control 1', [14, 16, '96', 4, 7, 12], [103.0, 25.8]],\n  ['generated control 2', [18, 16, '100', 5, 7, 16], [93.0, 23.3]],\n  ['generated control 3', [16, 16, '96', 5, 7, 14], [96.0, 24.0]]],\n [['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['unknown size', [12, 24, '92', 5, 6, 16], 'error: size'],\n  ['regression: step interval size', [6, 18, '92.5', 5, 7, 18], [122.5, 30.6]],\n  ['repair check: step interval size', [14, 10, '92.5', 5, 6, 12], [81.5, 20.4]],\n  ['generated control 1', [12, 14, '92.5', 5, 7, 18], [97.5, 24.4]],\n  ['generated control 2', [18, 10, '96', 4, 7, 14], [74.0, 18.5]],\n  ['generated control 3', [16, 14, '88', 4, 6, 14], [82.0, 20.5]]],\n [['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['unknown size', [12, 24, '92', 5, 6, 16], 'error: size'],\n  ['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['regression: step interval size', [10, 22, '88', 4, 6, 12], [122.0, 30.5]],\n  ['repair check: step interval size', [14, 10, '100', 4, 6, 14], [92.0, 23.0]],\n  ['generated control 1', [6, 6, '88', 4, 7, 14], [88.0, 22.0]],\n  ['generated control 2', [16, 22, '88', 4, 6, 14], [106.0, 26.5]],\n  ['generated control 3', [20, 20, '88', 5, 6, 16], [88.0, 22.0]]],\n [['unknown size', [12, 24, '92', 5, 6, 16], 'error: size'],\n  ['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['regression: step interval size', [10, 22, '88', 5, 7, 12], [128.0, 32.0]],\n  ['repair check: step interval size', [22, 14, '100', 5, 6, 16], [77.0, 19.3]],\n  ['generated control 1', [8, 6, '88', 5, 7, 16], [83.0, 20.8]],\n  ['generated control 2', [16, 20, '100', 5, 7, 14], [114.0, 28.5]],\n  ['generated control 3', [12, 6, '92.5', 5, 7, 14], [77.5, 19.4]]],\n [['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['regression: step interval size', [12, 20, '100', 4, 7, 18], [119.0, 29.8]],\n  ['repair check: step interval size', [18, 16, '96', 4, 6, 18], [92.0, 23.0]],\n  ['generated control 1', [10, 16, '100', 5, 6, 14], [116.0, 29.0]],\n  ['generated control 2', [12, 18, '100', 4, 7, 14], [118.0, 29.5]],\n  ['generated control 3', [16, 8, '96', 5, 7, 14], [74.0, 18.5]]]]\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":"0897b252d25ee0814b62b5c7316570b6e12f87e4590d6a5a1a31d8c38d8c5f7d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(base_size, target_size, base_cm, small, large, brk):\n    SIZES = [6, 8, 10, 12, 14, 16, 18, 20, 22]\n    if base_size not in SIZES or target_size not in SIZES:\n        return 'error: size'\n    i, j = SIZES.index(base_size), SIZES.index(target_size)\n    m = Fraction(str(base_cm))\n    step = 1 if j > i else -1\n    k = i\n    while k != j:\n        lo = k + step\n        inc = small if SIZES[lo] < brk else large\n        m += step * inc\n        k += step\n    q = m / 4\n    return [math.floor(m * 10 + Fraction(1, 2)) / 10, math.floor(q * 10 + Fraction(1, 2)) / 10]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['regression: step interval size', [10, 20, '92.5', 4, 6, 16], [116.5, 29.1]],\n  ['repair check: step interval size', [20, 8, '92.5', 4, 7, 16], [62.5, 15.6]],\n  ['generated control 1', [14, 16, '96', 4, 7, 12], [103.0, 25.8]],\n  ['generated control 2', [18, 16, '100', 5, 7, 16], [93.0, 23.3]],\n  ['generated control 3', [16, 16, '96', 5, 7, 14], [96.0, 24.0]]],\n [['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['unknown size', [12, 24, '92', 5, 6, 16], 'error: size'],\n  ['regression: step interval size', [6, 18, '92.5', 5, 7, 18], [122.5, 30.6]],\n  ['repair check: step interval size', [14, 10, '92.5', 5, 6, 12], [81.5, 20.4]],\n  ['generated control 1', [12, 14, '92.5', 5, 7, 18], [97.5, 24.4]],\n  ['generated control 2', [18, 10, '96', 4, 7, 14], [74.0, 18.5]],\n  ['generated control 3', [16, 14, '88', 4, 6, 14], [82.0, 20.5]]],\n [['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['unknown size', [12, 24, '92', 5, 6, 16], 'error: size'],\n  ['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['regression: step interval size', [10, 22, '88', 4, 6, 12], [122.0, 30.5]],\n  ['repair check: step interval size', [14, 10, '100', 4, 6, 14], [92.0, 23.0]],\n  ['generated control 1', [6, 6, '88', 4, 7, 14], [88.0, 22.0]],\n  ['generated control 2', [16, 22, '88', 4, 6, 14], [106.0, 26.5]],\n  ['generated control 3', [20, 20, '88', 5, 6, 16], [88.0, 22.0]]],\n [['unknown size', [12, 24, '92', 5, 6, 16], 'error: size'],\n  ['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['regression: step interval size', [10, 22, '88', 5, 7, 12], [128.0, 32.0]],\n  ['repair check: step interval size', [22, 14, '100', 5, 6, 16], [77.0, 19.3]],\n  ['generated control 1', [8, 6, '88', 5, 7, 16], [83.0, 20.8]],\n  ['generated control 2', [16, 20, '100', 5, 7, 14], [114.0, 28.5]],\n  ['generated control 3', [12, 6, '92.5', 5, 7, 14], [77.5, 19.4]]],\n [['same size', [12, 12, '92.5', 5, 6, 16], [92.5, 23.1]],\n  ['across the break', [14, 20, '96', 5, 6, 16], [113.0, 28.3]],\n  ['down across the break', [20, 14, '110', 5, 6, 16], [93.0, 23.3]],\n  ['regression: step interval size', [12, 20, '100', 4, 7, 18], [119.0, 29.8]],\n  ['repair check: step interval size', [18, 16, '96', 4, 6, 18], [92.0, 23.0]],\n  ['generated control 1', [10, 16, '100', 5, 6, 14], [116.0, 29.0]],\n  ['generated control 2', [12, 18, '100', 4, 7, 14], [118.0, 29.5]],\n  ['generated control 3', [16, 8, '96', 5, 7, 14], [74.0, 18.5]]]]\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 toy contract stated in full here; it is a bounded teaching model, not an authoritative reference or standards implementation. 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-knitting_and_sewing_pattern_grading-grade-rules-step-interval-size","generated_at":"2026-09-29T14:52:33.008192+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Sewing pattern grading applies different increments above a size break and distributes them across front and back pieces.","root_cause":"The increment is chosen from the destination size of each step instead of its lower size.","sha256":"4e772b70040204e9bd74af8df53be01c22d87de10d5260e7171529869cd275c0","title":"Sewing pattern grade rule stepper: step interval size · 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":43.46,"exit_code":1,"observations":[{"actual":[92.5,23.1],"check":"same size","expected":[92.5,23.1],"passed":true},{"actual":[113.0,28.3],"check":"across the break","expected":[113.0,28.3],"passed":true},{"actual":[92.0,23.0],"check":"down across the break","expected":[93.0,23.3],"passed":false},{"actual":[116.5,29.1],"check":"regression: step interval size","expected":[116.5,29.1],"passed":true},{"actual":[59.5,14.9],"check":"repair check: step interval size","expected":[62.5,15.6],"passed":false},{"actual":[103.0,25.8],"check":"generated control 1","expected":[103.0,25.8],"passed":true},{"actual":[93.0,23.3],"check":"generated control 2","expected":[93.0,23.3],"passed":true},{"actual":[96.0,24.0],"check":"generated control 3","expected":[96.0,24.0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"same size\", \"actual\": [92.5, 23.1], \"expected\": [92.5, 23.1], \"passed\": true}, {\"check\": \"across the break\", \"actual\": [113.0, 28.3], \"expected\": [113.0, 28.3], \"passed\": true}, {\"check\": \"down across the break\", \"actual\": [92.0, 23.0], \"expected\": [93.0, 23.3], \"passed\": false}, {\"check\": \"regression: step interval size\", \"actual\": [116.5, 29.1], \"expected\": [116.5, 29.1], \"passed\": true}, {\"check\": \"repair check: step interval size\", \"actual\": [59.5, 14.9], \"expected\": [62.5, 15.6], \"passed\": false}, {\"check\": \"generated control 1\", \"actual\": [103.0, 25.8], \"expected\": [103.0, 25.8], \"passed\": true}, {\"check\": \"generated control 2\", \"actual\": [93.0, 23.3], \"expected\": [93.0, 23.3], \"passed\": true}, {\"check\": \"generated control 3\", \"actual\": [96.0, 24.0], \"expected\": [96.0, 24.0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":44.364,"exit_code":1,"observations":[{"actual":[92.5,23.1],"check":"same size","expected":[92.5,23.1],"passed":true},{"actual":[114.0,28.5],"check":"across the break","expected":[113.0,28.3],"passed":false},{"actual":[93.0,23.3],"check":"down across the break","expected":[93.0,23.3],"passed":true},{"actual":[118.5,29.6],"check":"regression: step interval size","expected":[116.5,29.1],"passed":false},{"actual":[62.5,15.6],"check":"repair check: step interval size","expected":[62.5,15.6],"passed":true},{"actual":[103.0,25.8],"check":"generated control 1","expected":[103.0,25.8],"passed":true},{"actual":[93.0,23.3],"check":"generated control 2","expected":[93.0,23.3],"passed":true},{"actual":[96.0,24.0],"check":"generated control 3","expected":[96.0,24.0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"same size\", \"actual\": [92.5, 23.1], \"expected\": [92.5, 23.1], \"passed\": true}, {\"check\": \"across the break\", \"actual\": [114.0, 28.5], \"expected\": [113.0, 28.3], \"passed\": false}, {\"check\": \"down across the break\", \"actual\": [93.0, 23.3], \"expected\": [93.0, 23.3], \"passed\": true}, {\"check\": \"regression: step interval size\", \"actual\": [118.5, 29.6], \"expected\": [116.5, 29.1], \"passed\": false}, {\"check\": \"repair check: step interval size\", \"actual\": [62.5, 15.6], \"expected\": [62.5, 15.6], \"passed\": true}, {\"check\": \"generated control 1\", \"actual\": [103.0, 25.8], \"expected\": [103.0, 25.8], \"passed\": true}, {\"check\": \"generated control 2\", \"actual\": [93.0, 23.3], \"expected\": [93.0, 23.3], \"passed\": true}, {\"check\": \"generated control 3\", \"actual\": [96.0, 24.0], \"expected\": [96.0, 24.0], \"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."}}