{"abstract":"Going from 53 to 48 stitches is accepted and one stitch vanishes.","category":"Knitting and sewing pattern grading","checks":8,"contract":"Top-down sleeve from upper_sts to cuff_sts, decreasing 2 stitches per decrease row within rows rows. Errors: cuff wider (\"error: cuff wider than upper arm\"), odd difference (\"error: odd difference\"), rows fewer than decrease rows (\"error: not enough rows\"). pairs = difference/2; a = rows // pairs; y = rows - a*pairs decreases every a+1 rows, x = pairs-y every a rows. Return [[a, x], [a+1, y]] omitting a zero count; [] for no decreases.","evaluation_group":"w2-knitting_and_sewing_pattern_grading-sleeve-taper","failed_approach":"Checking the cuff count is just as unrelated to the difference.","family":"w2-knitting_and_sewing_pattern_grading-sleeve-taper-odd-difference-test","id":"FA-97386","implementations":{"attempt":{"sha256":"4532dd6984681381964f15b6f378bbaab7df3d83046ba14576d8f1ee5b72f754","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(cuff_sts, upper_sts, rows):\n    diff = upper_sts - cuff_sts\n    if diff < 0:\n        return 'error: cuff wider than upper arm'\n    if cuff_sts % 2:\n        return 'error: odd difference'\n    pairs = diff // 2\n    if pairs == 0:\n        return []\n    a = rows // pairs\n    if a == 0:\n        return 'error: not enough rows'\n    y = rows - a * pairs\n    x = pairs - y\n    plan = []\n    if x:\n        plan.append([a, x])\n    if y:\n        plan.append([a + 1, y])\n    return plan\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['even schedule', [48, 64, 80], [[10, 8]]], ['two rates', [44, 60, 90], [[11, 6], [12, 2]]],\n  ['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['regression: odd difference test', [51, 58, 40], 'error: odd difference'],\n  ['repair check: odd difference test', [40, 47, 10], 'error: odd difference'],\n  ['generated control 1', [60, 68, 5], [[1, 3], [2, 1]]], ['generated control 2', [44, 52, 60], [[15, 4]]],\n  ['generated control 3', [56, 68, 10], [[1, 2], [2, 4]]]],\n [['two rates', [44, 60, 90], [[11, 6], [12, 2]]], ['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['regression: odd difference test', [51, 59, 40], [[10, 4]]],\n  ['repair check: odd difference test', [51, 51, 5], []], ['generated control 1', [44, 46, 40], [[40, 1]]],\n  ['generated control 2', [40, 60, 40], [[4, 10]]], ['generated control 3', [48, 60, 40], [[6, 2], [7, 4]]]],\n [['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['regression: odd difference test', [51, 71, 40], [[4, 10]]],\n  ['repair check: odd difference test', [48, 55, 40], 'error: odd difference'],\n  ['generated control 1', [60, 76, 5], 'error: not enough rows'],\n  ['generated control 2', [40, 45, 72], 'error: odd difference'], ['generated control 3', [40, 40, 5], []]],\n [['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['even schedule', [48, 64, 80], [[10, 8]]],\n  ['regression: odd difference test', [45, 52, 72], 'error: odd difference'],\n  ['repair check: odd difference test', [40, 47, 100], 'error: odd difference'],\n  ['generated control 1', [56, 72, 100], [[12, 4], [13, 4]]],\n  ['generated control 2', [44, 60, 10], [[1, 6], [2, 2]]], ['generated control 3', [60, 80, 60], [[6, 10]]]],\n [['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['even schedule', [48, 64, 80], [[10, 8]]], ['two rates', [44, 60, 90], [[11, 6], [12, 2]]],\n  ['regression: odd difference test', [51, 53, 40], [[40, 1]]],\n  ['repair check: odd difference test', [60, 67, 90], 'error: odd difference'],\n  ['generated control 1', [44, 60, 60], [[7, 4], [8, 4]]], ['generated control 2', [50, 52, 10], [[10, 1]]],\n  ['generated control 3', [48, 60, 10], [[1, 2], [2, 4]]]]]\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":"b6e49cfb3acf2f8a47876b9241bb4635a50d8c1506e0cccd63a90add7a35475a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(cuff_sts, upper_sts, rows):\n    diff = upper_sts - cuff_sts\n    if diff < 0:\n        return 'error: cuff wider than upper arm'\n    if upper_sts % 2:\n        return 'error: odd difference'\n    pairs = diff // 2\n    if pairs == 0:\n        return []\n    a = rows // pairs\n    if a == 0:\n        return 'error: not enough rows'\n    y = rows - a * pairs\n    x = pairs - y\n    plan = []\n    if x:\n        plan.append([a, x])\n    if y:\n        plan.append([a + 1, y])\n    return plan\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['even schedule', [48, 64, 80], [[10, 8]]], ['two rates', [44, 60, 90], [[11, 6], [12, 2]]],\n  ['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['regression: odd difference test', [51, 58, 40], 'error: odd difference'],\n  ['repair check: odd difference test', [40, 47, 10], 'error: odd difference'],\n  ['generated control 1', [60, 68, 5], [[1, 3], [2, 1]]], ['generated control 2', [44, 52, 60], [[15, 4]]],\n  ['generated control 3', [56, 68, 10], [[1, 2], [2, 4]]]],\n [['two rates', [44, 60, 90], [[11, 6], [12, 2]]], ['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['regression: odd difference test', [51, 59, 40], [[10, 4]]],\n  ['repair check: odd difference test', [51, 51, 5], []], ['generated control 1', [44, 46, 40], [[40, 1]]],\n  ['generated control 2', [40, 60, 40], [[4, 10]]], ['generated control 3', [48, 60, 40], [[6, 2], [7, 4]]]],\n [['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['regression: odd difference test', [51, 71, 40], [[4, 10]]],\n  ['repair check: odd difference test', [48, 55, 40], 'error: odd difference'],\n  ['generated control 1', [60, 76, 5], 'error: not enough rows'],\n  ['generated control 2', [40, 45, 72], 'error: odd difference'], ['generated control 3', [40, 40, 5], []]],\n [['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['even schedule', [48, 64, 80], [[10, 8]]],\n  ['regression: odd difference test', [45, 52, 72], 'error: odd difference'],\n  ['repair check: odd difference test', [40, 47, 100], 'error: odd difference'],\n  ['generated control 1', [56, 72, 100], [[12, 4], [13, 4]]],\n  ['generated control 2', [44, 60, 10], [[1, 6], [2, 2]]], ['generated control 3', [60, 80, 60], [[6, 10]]]],\n [['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['even schedule', [48, 64, 80], [[10, 8]]], ['two rates', [44, 60, 90], [[11, 6], [12, 2]]],\n  ['regression: odd difference test', [51, 53, 40], [[40, 1]]],\n  ['repair check: odd difference test', [60, 67, 90], 'error: odd difference'],\n  ['generated control 1', [44, 60, 60], [[7, 4], [8, 4]]], ['generated control 2', [50, 52, 10], [[10, 1]]],\n  ['generated control 3', [48, 60, 10], [[1, 2], [2, 4]]]]]\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":"d35d1c04557fc1d20a368284c6f0da03c6ca6bcccef42eed7b254d95dd984756","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nfrom fractions import Fraction\nN = 1\nobservations = []\ndef solve(cuff_sts, upper_sts, rows):\n    diff = upper_sts - cuff_sts\n    if diff < 0:\n        return 'error: cuff wider than upper arm'\n    if diff % 2:\n        return 'error: odd difference'\n    pairs = diff // 2\n    if pairs == 0:\n        return []\n    a = rows // pairs\n    if a == 0:\n        return 'error: not enough rows'\n    y = rows - a * pairs\n    x = pairs - y\n    plan = []\n    if x:\n        plan.append([a, x])\n    if y:\n        plan.append([a + 1, y])\n    return plan\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['even schedule', [48, 64, 80], [[10, 8]]], ['two rates', [44, 60, 90], [[11, 6], [12, 2]]],\n  ['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['regression: odd difference test', [51, 58, 40], 'error: odd difference'],\n  ['repair check: odd difference test', [40, 47, 10], 'error: odd difference'],\n  ['generated control 1', [60, 68, 5], [[1, 3], [2, 1]]], ['generated control 2', [44, 52, 60], [[15, 4]]],\n  ['generated control 3', [56, 68, 10], [[1, 2], [2, 4]]]],\n [['two rates', [44, 60, 90], [[11, 6], [12, 2]]], ['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['regression: odd difference test', [51, 59, 40], [[10, 4]]],\n  ['repair check: odd difference test', [51, 51, 5], []], ['generated control 1', [44, 46, 40], [[40, 1]]],\n  ['generated control 2', [40, 60, 40], [[4, 10]]], ['generated control 3', [48, 60, 40], [[6, 2], [7, 4]]]],\n [['odd difference', [48, 53, 60], 'error: odd difference'],\n  ['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['regression: odd difference test', [51, 71, 40], [[4, 10]]],\n  ['repair check: odd difference test', [48, 55, 40], 'error: odd difference'],\n  ['generated control 1', [60, 76, 5], 'error: not enough rows'],\n  ['generated control 2', [40, 45, 72], 'error: odd difference'], ['generated control 3', [40, 40, 5], []]],\n [['too few rows', [40, 70, 10], 'error: not enough rows'],\n  ['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['even schedule', [48, 64, 80], [[10, 8]]],\n  ['regression: odd difference test', [45, 52, 72], 'error: odd difference'],\n  ['repair check: odd difference test', [40, 47, 100], 'error: odd difference'],\n  ['generated control 1', [56, 72, 100], [[12, 4], [13, 4]]],\n  ['generated control 2', [44, 60, 10], [[1, 6], [2, 2]]], ['generated control 3', [60, 80, 60], [[6, 10]]]],\n [['cuff wider', [60, 50, 60], 'error: cuff wider than upper arm'],\n  ['even schedule', [48, 64, 80], [[10, 8]]], ['two rates', [44, 60, 90], [[11, 6], [12, 2]]],\n  ['regression: odd difference test', [51, 53, 40], [[40, 1]]],\n  ['repair check: odd difference test', [60, 67, 90], 'error: odd difference'],\n  ['generated control 1', [44, 60, 60], [[7, 4], [8, 4]]], ['generated control 2', [50, 52, 10], [[10, 1]]],\n  ['generated control 3', [48, 60, 10], [[1, 2], [2, 4]]]]]\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-sleeve-taper-odd-difference-test","generated_at":"2026-09-29T14:52:31.692936+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Pattern writers turn a stitch-count change over a length into \"decrease every N rows X times\".","repair":"Reject an odd stitch difference.","root_cause":"Parity is checked on the upper-arm count instead of the difference.","sha256":"577084361f55c2218dad4a27c611b48523aee005e6056c74672b54a19e5bda0f","title":"Sleeve taper decrease schedule: odd difference test · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.364,"exit_code":1,"observations":[{"actual":[[10,8]],"check":"even schedule","expected":[[10,8]],"passed":true},{"actual":[[11,6],[12,2]],"check":"two rates","expected":[[11,6],[12,2]],"passed":true},{"actual":[[30,2]],"check":"odd difference","expected":"error: odd difference","passed":false},{"actual":"error: odd difference","check":"regression: odd difference test","expected":"error: odd difference","passed":true},{"actual":[[3,2],[4,1]],"check":"repair check: odd difference test","expected":"error: odd difference","passed":false},{"actual":[[1,3],[2,1]],"check":"generated control 1","expected":[[1,3],[2,1]],"passed":true},{"actual":[[15,4]],"check":"generated control 2","expected":[[15,4]],"passed":true},{"actual":[[1,2],[2,4]],"check":"generated control 3","expected":[[1,2],[2,4]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"even schedule\", \"actual\": [[10, 8]], \"expected\": [[10, 8]], \"passed\": true}, {\"check\": \"two rates\", \"actual\": [[11, 6], [12, 2]], \"expected\": [[11, 6], [12, 2]], \"passed\": true}, {\"check\": \"odd difference\", \"actual\": [[30, 2]], \"expected\": \"error: odd difference\", \"passed\": false}, {\"check\": \"regression: odd difference test\", \"actual\": \"error: odd difference\", \"expected\": \"error: odd difference\", \"passed\": true}, {\"check\": \"repair check: odd difference test\", \"actual\": [[3, 2], [4, 1]], \"expected\": \"error: odd difference\", \"passed\": false}, {\"check\": \"generated control 1\", \"actual\": [[1, 3], [2, 1]], \"expected\": [[1, 3], [2, 1]], \"passed\": true}, {\"check\": \"generated control 2\", \"actual\": [[15, 4]], \"expected\": [[15, 4]], \"passed\": true}, {\"check\": \"generated control 3\", \"actual\": [[1, 2], [2, 4]], \"expected\": [[1, 2], [2, 4]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":43.913,"exit_code":1,"observations":[{"actual":[[10,8]],"check":"even schedule","expected":[[10,8]],"passed":true},{"actual":[[11,6],[12,2]],"check":"two rates","expected":[[11,6],[12,2]],"passed":true},{"actual":"error: odd difference","check":"odd difference","expected":"error: odd difference","passed":true},{"actual":[[13,2],[14,1]],"check":"regression: odd difference test","expected":"error: odd difference","passed":false},{"actual":"error: odd difference","check":"repair check: odd difference test","expected":"error: odd difference","passed":true},{"actual":[[1,3],[2,1]],"check":"generated control 1","expected":[[1,3],[2,1]],"passed":true},{"actual":[[15,4]],"check":"generated control 2","expected":[[15,4]],"passed":true},{"actual":[[1,2],[2,4]],"check":"generated control 3","expected":[[1,2],[2,4]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"even schedule\", \"actual\": [[10, 8]], \"expected\": [[10, 8]], \"passed\": true}, {\"check\": \"two rates\", \"actual\": [[11, 6], [12, 2]], \"expected\": [[11, 6], [12, 2]], \"passed\": true}, {\"check\": \"odd difference\", \"actual\": \"error: odd difference\", \"expected\": \"error: odd difference\", \"passed\": true}, {\"check\": \"regression: odd difference test\", \"actual\": [[13, 2], [14, 1]], \"expected\": \"error: odd difference\", \"passed\": false}, {\"check\": \"repair check: odd difference test\", \"actual\": \"error: odd difference\", \"expected\": \"error: odd difference\", \"passed\": true}, {\"check\": \"generated control 1\", \"actual\": [[1, 3], [2, 1]], \"expected\": [[1, 3], [2, 1]], \"passed\": true}, {\"check\": \"generated control 2\", \"actual\": [[15, 4]], \"expected\": [[15, 4]], \"passed\": true}, {\"check\": \"generated control 3\", \"actual\": [[1, 2], [2, 4]], \"expected\": [[1, 2], [2, 4]], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":43.752,"exit_code":0,"observations":[{"actual":[[10,8]],"check":"even schedule","expected":[[10,8]],"passed":true},{"actual":[[11,6],[12,2]],"check":"two rates","expected":[[11,6],[12,2]],"passed":true},{"actual":"error: odd difference","check":"odd difference","expected":"error: odd difference","passed":true},{"actual":"error: odd difference","check":"regression: odd difference test","expected":"error: odd difference","passed":true},{"actual":"error: odd difference","check":"repair check: odd difference test","expected":"error: odd difference","passed":true},{"actual":[[1,3],[2,1]],"check":"generated control 1","expected":[[1,3],[2,1]],"passed":true},{"actual":[[15,4]],"check":"generated control 2","expected":[[15,4]],"passed":true},{"actual":[[1,2],[2,4]],"check":"generated control 3","expected":[[1,2],[2,4]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"even schedule\", \"actual\": [[10, 8]], \"expected\": [[10, 8]], \"passed\": true}, {\"check\": \"two rates\", \"actual\": [[11, 6], [12, 2]], \"expected\": [[11, 6], [12, 2]], \"passed\": true}, {\"check\": \"odd difference\", \"actual\": \"error: odd difference\", \"expected\": \"error: odd difference\", \"passed\": true}, {\"check\": \"regression: odd difference test\", \"actual\": \"error: odd difference\", \"expected\": \"error: odd difference\", \"passed\": true}, {\"check\": \"repair check: odd difference test\", \"actual\": \"error: odd difference\", \"expected\": \"error: odd difference\", \"passed\": true}, {\"check\": \"generated control 1\", \"actual\": [[1, 3], [2, 1]], \"expected\": [[1, 3], [2, 1]], \"passed\": true}, {\"check\": \"generated control 2\", \"actual\": [[15, 4]], \"expected\": [[15, 4]], \"passed\": true}, {\"check\": \"generated control 3\", \"actual\": [[1, 2], [2, 4]], \"expected\": [[1, 2], [2, 4]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}