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FA-97771 / Knitting and sewing pattern grading / Open access

Top-down raglan setup: front share · case 01

Sleeves at the neck are as wide as the front.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The neck is split into equal quarters instead of front/back thirds.

VERIFIED REPAIR

Front takes a third of the remaining stitches.

Unsuccessful approach: Rounding the third can leave sleeves too small.

Case contract

neck_sts < 16 -> "error: neck too small". Reserve 4 raglan seam stitches; rem = neck-4; front = rem//3; sleeves share rem - 2*front, each sleeve half of that, and an odd leftover goes to the back (back = front + leftover%2). Each increase round adds 2 to front (and back); rounds = max(0, ceiling((underarm_body_sts//2 - front)/2)). yoke_total = neck + 8*rounds.

Why this case matters

Top-down raglan sweaters split the neck cast-on among front, back, sleeves and seam stitches.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(neck_sts, underarm_body_sts):
    if neck_sts < 16:
        return 'error: neck too small'
    rem = neck_sts - 4
    front = rem // 4
    sleeves_total = rem - 2 * front
    sleeve = sleeves_total // 2
    back = front + sleeves_total % 2
    target = underarm_body_sts // 2
    incs = max(0, math.ceil(Fraction(target - front, 2)))
    return {'front': front, 'back': back, 'sleeve': sleeve, 'raglan': 4, 'increase_rounds': incs,
            'yoke_total': neck_sts + 8 * incs}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['regression: front share', [110, 180],
   {'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}],
  ['repair check: front share', [120, 160],
   {'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}],
  ['generated control 1', [100, 201],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['generated control 2', [16, 200],
   {'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}],
  ['generated control 3', [12, 160], 'error: neck too small']],
 [['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['regression: front share', [88, 60],
   {'back': 28, 'front': 28, 'increase_rounds': 1, 'raglan': 4, 'sleeve': 14, 'yoke_total': 96}],
  ['repair check: front share', [120, 201],
   {'back': 38, 'front': 38, 'increase_rounds': 31, 'raglan': 4, 'sleeve': 20, 'yoke_total': 368}],
  ['generated control 1', [100, 201],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['generated control 2', [12, 200], 'error: neck too small'],
  ['generated control 3', [100, 160],
   {'back': 32, 'front': 32, 'increase_rounds': 24, 'raglan': 4, 'sleeve': 16, 'yoke_total': 292}]],
 [['tiny neck', [12, 100], 'error: neck too small'],
  ['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['regression: front share', [120, 220],
   {'back': 38, 'front': 38, 'increase_rounds': 36, 'raglan': 4, 'sleeve': 20, 'yoke_total': 408}],
  ['repair check: front share', [96, 60],
   {'back': 30, 'front': 30, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 16, 'yoke_total': 96}],
  ['generated control 1', [101, 200],
   {'back': 33, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 373}],
  ['generated control 2', [100, 60],
   {'back': 32, 'front': 32, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 16, 'yoke_total': 100}],
  ['generated control 3', [16, 200],
   {'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}]],
 [['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['regression: front share', [80, 200],
   {'back': 25, 'front': 25, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 13, 'yoke_total': 384}],
  ['repair check: front share', [120, 160],
   {'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}],
  ['generated control 1', [120, 180],
   {'back': 38, 'front': 38, 'increase_rounds': 26, 'raglan': 4, 'sleeve': 20, 'yoke_total': 328}],
  ['generated control 2', [101, 160],
   {'back': 33, 'front': 32, 'increase_rounds': 24, 'raglan': 4, 'sleeve': 16, 'yoke_total': 293}],
  ['generated control 3', [100, 220],
   {'back': 32, 'front': 32, 'increase_rounds': 39, 'raglan': 4, 'sleeve': 16, 'yoke_total': 412}]],
 [['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['regression: front share', [16, 60],
   {'back': 4, 'front': 4, 'increase_rounds': 13, 'raglan': 4, 'sleeve': 2, 'yoke_total': 120}],
  ['repair check: front share', [120, 80],
   {'back': 38, 'front': 38, 'increase_rounds': 1, 'raglan': 4, 'sleeve': 20, 'yoke_total': 128}],
  ['generated control 1', [80, 180],
   {'back': 25, 'front': 25, 'increase_rounds': 33, 'raglan': 4, 'sleeve': 13, 'yoke_total': 344}],
  ['generated control 2', [16, 160],
   {'back': 4, 'front': 4, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 2, 'yoke_total': 320}],
  ['generated control 3', [88, 200],
   {'back': 28, 'front': 28, 'increase_rounds': 36, 'raglan': 4, 'sleeve': 14, 'yoke_total': 376}]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
standard neck{'back': 24, 'front': 24, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 24, 'yoke_total': 404}{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}Failed
odd leftover{'back': 25, 'front': 24, 'increase_rounds': 33, 'raglan': 4, 'sleeve': 24, 'yoke_total': 365}{'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}Failed
tiny neckerror: neck too smallerror: neck too smallPassed
regression: front share{'back': 26, 'front': 26, 'increase_rounds': 32, 'raglan': 4, 'sleeve': 27, 'yoke_total': 366}{'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}Failed
repair check: front share{'back': 29, 'front': 29, 'increase_rounds': 26, 'raglan': 4, 'sleeve': 29, 'yoke_total': 328}{'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}Failed
generated control 1{'back': 24, 'front': 24, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 24, 'yoke_total': 404}{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}Failed
generated control 2{'back': 3, 'front': 3, 'increase_rounds': 49, 'raglan': 4, 'sleeve': 3, 'yoke_total': 408}{'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}Failed
generated control 3error: neck too smallerror: neck too smallPassed

SHA-256 / cfbcb3ec59a0cd08849117052a4cbb1b8256910799110cff851d045f594434d0

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(neck_sts, underarm_body_sts):
    if neck_sts < 16:
        return 'error: neck too small'
    rem = neck_sts - 4
    front = math.floor(Fraction(rem, 3) + Fraction(1, 2))
    sleeves_total = rem - 2 * front
    sleeve = sleeves_total // 2
    back = front + sleeves_total % 2
    target = underarm_body_sts // 2
    incs = max(0, math.ceil(Fraction(target - front, 2)))
    return {'front': front, 'back': back, 'sleeve': sleeve, 'raglan': 4, 'increase_rounds': incs,
            'yoke_total': neck_sts + 8 * incs}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['regression: front share', [110, 180],
   {'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}],
  ['repair check: front share', [120, 160],
   {'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}],
  ['generated control 1', [100, 201],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['generated control 2', [16, 200],
   {'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}],
  ['generated control 3', [12, 160], 'error: neck too small']],
 [['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['regression: front share', [88, 60],
   {'back': 28, 'front': 28, 'increase_rounds': 1, 'raglan': 4, 'sleeve': 14, 'yoke_total': 96}],
  ['repair check: front share', [120, 201],
   {'back': 38, 'front': 38, 'increase_rounds': 31, 'raglan': 4, 'sleeve': 20, 'yoke_total': 368}],
  ['generated control 1', [100, 201],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['generated control 2', [12, 200], 'error: neck too small'],
  ['generated control 3', [100, 160],
   {'back': 32, 'front': 32, 'increase_rounds': 24, 'raglan': 4, 'sleeve': 16, 'yoke_total': 292}]],
 [['tiny neck', [12, 100], 'error: neck too small'],
  ['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['regression: front share', [120, 220],
   {'back': 38, 'front': 38, 'increase_rounds': 36, 'raglan': 4, 'sleeve': 20, 'yoke_total': 408}],
  ['repair check: front share', [96, 60],
   {'back': 30, 'front': 30, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 16, 'yoke_total': 96}],
  ['generated control 1', [101, 200],
   {'back': 33, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 373}],
  ['generated control 2', [100, 60],
   {'back': 32, 'front': 32, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 16, 'yoke_total': 100}],
  ['generated control 3', [16, 200],
   {'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}]],
 [['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['regression: front share', [80, 200],
   {'back': 25, 'front': 25, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 13, 'yoke_total': 384}],
  ['repair check: front share', [120, 160],
   {'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}],
  ['generated control 1', [120, 180],
   {'back': 38, 'front': 38, 'increase_rounds': 26, 'raglan': 4, 'sleeve': 20, 'yoke_total': 328}],
  ['generated control 2', [101, 160],
   {'back': 33, 'front': 32, 'increase_rounds': 24, 'raglan': 4, 'sleeve': 16, 'yoke_total': 293}],
  ['generated control 3', [100, 220],
   {'back': 32, 'front': 32, 'increase_rounds': 39, 'raglan': 4, 'sleeve': 16, 'yoke_total': 412}]],
 [['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['regression: front share', [16, 60],
   {'back': 4, 'front': 4, 'increase_rounds': 13, 'raglan': 4, 'sleeve': 2, 'yoke_total': 120}],
  ['repair check: front share', [120, 80],
   {'back': 38, 'front': 38, 'increase_rounds': 1, 'raglan': 4, 'sleeve': 20, 'yoke_total': 128}],
  ['generated control 1', [80, 180],
   {'back': 25, 'front': 25, 'increase_rounds': 33, 'raglan': 4, 'sleeve': 13, 'yoke_total': 344}],
  ['generated control 2', [16, 160],
   {'back': 4, 'front': 4, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 2, 'yoke_total': 320}],
  ['generated control 3', [88, 200],
   {'back': 28, 'front': 28, 'increase_rounds': 36, 'raglan': 4, 'sleeve': 14, 'yoke_total': 376}]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
standard neck{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}Passed
odd leftover{'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}{'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}Passed
tiny neckerror: neck too smallerror: neck too smallPassed
regression: front share{'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}{'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}Passed
repair check: front share{'back': 39, 'front': 39, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 19, 'yoke_total': 288}{'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}Failed
generated control 1{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}Passed
generated control 2{'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}{'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}Passed
generated control 3error: neck too smallerror: neck too smallPassed

SHA-256 / 2273050c20e6256b9fa31753024e7b0ddb900aab7e6f8ddc4299940c1afb3342

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
from fractions import Fraction
N = 1
observations = []
def solve(neck_sts, underarm_body_sts):
    if neck_sts < 16:
        return 'error: neck too small'
    rem = neck_sts - 4
    front = rem // 3
    sleeves_total = rem - 2 * front
    sleeve = sleeves_total // 2
    back = front + sleeves_total % 2
    target = underarm_body_sts // 2
    incs = max(0, math.ceil(Fraction(target - front, 2)))
    return {'front': front, 'back': back, 'sleeve': sleeve, 'raglan': 4, 'increase_rounds': incs,
            'yoke_total': neck_sts + 8 * incs}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['regression: front share', [110, 180],
   {'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}],
  ['repair check: front share', [120, 160],
   {'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}],
  ['generated control 1', [100, 201],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['generated control 2', [16, 200],
   {'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}],
  ['generated control 3', [12, 160], 'error: neck too small']],
 [['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['regression: front share', [88, 60],
   {'back': 28, 'front': 28, 'increase_rounds': 1, 'raglan': 4, 'sleeve': 14, 'yoke_total': 96}],
  ['repair check: front share', [120, 201],
   {'back': 38, 'front': 38, 'increase_rounds': 31, 'raglan': 4, 'sleeve': 20, 'yoke_total': 368}],
  ['generated control 1', [100, 201],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['generated control 2', [12, 200], 'error: neck too small'],
  ['generated control 3', [100, 160],
   {'back': 32, 'front': 32, 'increase_rounds': 24, 'raglan': 4, 'sleeve': 16, 'yoke_total': 292}]],
 [['tiny neck', [12, 100], 'error: neck too small'],
  ['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['regression: front share', [120, 220],
   {'back': 38, 'front': 38, 'increase_rounds': 36, 'raglan': 4, 'sleeve': 20, 'yoke_total': 408}],
  ['repair check: front share', [96, 60],
   {'back': 30, 'front': 30, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 16, 'yoke_total': 96}],
  ['generated control 1', [101, 200],
   {'back': 33, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 373}],
  ['generated control 2', [100, 60],
   {'back': 32, 'front': 32, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 16, 'yoke_total': 100}],
  ['generated control 3', [16, 200],
   {'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}]],
 [['already wide', [120, 60],
   {'back': 38, 'front': 38, 'increase_rounds': 0, 'raglan': 4, 'sleeve': 20, 'yoke_total': 120}],
  ['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['regression: front share', [80, 200],
   {'back': 25, 'front': 25, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 13, 'yoke_total': 384}],
  ['repair check: front share', [120, 160],
   {'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}],
  ['generated control 1', [120, 180],
   {'back': 38, 'front': 38, 'increase_rounds': 26, 'raglan': 4, 'sleeve': 20, 'yoke_total': 328}],
  ['generated control 2', [101, 160],
   {'back': 33, 'front': 32, 'increase_rounds': 24, 'raglan': 4, 'sleeve': 16, 'yoke_total': 293}],
  ['generated control 3', [100, 220],
   {'back': 32, 'front': 32, 'increase_rounds': 39, 'raglan': 4, 'sleeve': 16, 'yoke_total': 412}]],
 [['standard neck', [100, 200],
   {'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}],
  ['odd leftover', [101, 180],
   {'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}],
  ['tiny neck', [12, 100], 'error: neck too small'],
  ['regression: front share', [16, 60],
   {'back': 4, 'front': 4, 'increase_rounds': 13, 'raglan': 4, 'sleeve': 2, 'yoke_total': 120}],
  ['repair check: front share', [120, 80],
   {'back': 38, 'front': 38, 'increase_rounds': 1, 'raglan': 4, 'sleeve': 20, 'yoke_total': 128}],
  ['generated control 1', [80, 180],
   {'back': 25, 'front': 25, 'increase_rounds': 33, 'raglan': 4, 'sleeve': 13, 'yoke_total': 344}],
  ['generated control 2', [16, 160],
   {'back': 4, 'front': 4, 'increase_rounds': 38, 'raglan': 4, 'sleeve': 2, 'yoke_total': 320}],
  ['generated control 3', [88, 200],
   {'back': 28, 'front': 28, 'increase_rounds': 36, 'raglan': 4, 'sleeve': 14, 'yoke_total': 376}]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
standard neck{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}Passed
odd leftover{'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}{'back': 33, 'front': 32, 'increase_rounds': 29, 'raglan': 4, 'sleeve': 16, 'yoke_total': 333}Passed
tiny neckerror: neck too smallerror: neck too smallPassed
regression: front share{'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}{'back': 35, 'front': 35, 'increase_rounds': 28, 'raglan': 4, 'sleeve': 18, 'yoke_total': 334}Passed
repair check: front share{'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}{'back': 38, 'front': 38, 'increase_rounds': 21, 'raglan': 4, 'sleeve': 20, 'yoke_total': 288}Passed
generated control 1{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}{'back': 32, 'front': 32, 'increase_rounds': 34, 'raglan': 4, 'sleeve': 16, 'yoke_total': 372}Passed
generated control 2{'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}{'back': 4, 'front': 4, 'increase_rounds': 48, 'raglan': 4, 'sleeve': 2, 'yoke_total': 400}Passed
generated control 3error: neck too smallerror: neck too smallPassed

SHA-256 / e19a49ffbfd916c4c933191cc901a2b4400320f37e89887094be71b87585154a

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:52:35.472223+00:00.

Case digest / 31775cfd9f47460f2ee056e948317127275c549f2e2e38e0100eb3eeedde0c8e