FA-95346 / Shipping rate zone lookup / Open access

Zone chart: four-digit New England ZIPs invalid · case 01

ZIPs that lost their leading zero in a spreadsheet export are rejected.

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

ROOT CAUSE

Four-digit numeric ZIPs are not restored before length validation.

VERIFIED REPAIR

Left-pad four-digit numeric ZIPs with one zero.

Unsuccessful approach: Right-padding produces a different, wrong ZIP3.

Case contract

dest is a ZIP string with optional surrounding whitespace, optionally ZIP+4 ("12345-6789"), or a 4-digit ZIP whose leading zero was lost (left-pad one zero). chart [[lo3, hi3, zone]] inclusive ZIP3 ranges; the narrowest matching range wins, earliest listed on equal width. Malformed -> "INVALID"; no match -> "NO_ZONE".

Why this case matters

Carrier zone charts map origin to destination ZIP3 ranges, the first step of rating.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(dest, chart):
    z = dest.strip()
    if len(z) == 10 and z[5] == '-' and z[6:].isdecimal():
        z = z[:5]
    if len(z) != 5 or not z.isdecimal():
        return 'INVALID'
    p = int(z[:3])
    best = None
    for lo, hi, zone in chart:
        if lo <= p <= hi:
            if best is None or (hi - lo) < (best[1] - best[0]):
                best = (lo, hi, zone)
    return best[2] if best else 'NO_ZONE'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 4', ['10001-12a4', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 7', ['09999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 15', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5]], [['generated mix 75', ['0501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 17', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 25', ['15999-123', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 29', ['02134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 37', ['\t21000\n', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 2], ['generated mix 45', ['15999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4]], [['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['generated mix 40', ['00501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 48', ['10001', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 56', ['21499', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 2]]]
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 fixture	Actual	Expected	Outcome
lost leading zero	`INVALID`	`8`	Failed
generated mix 38	`INVALID`	`8`	Failed
zip plus four	`4`	`4`	Passed
nested narrowest	`6`	`6`	Passed
equal width higher zone first	`9`	`9`	Passed
letters	`INVALID`	`INVALID`	Passed
range upper edge	`5`	`5`	Passed
generated mix 4	`INVALID`	`INVALID`	Passed

SHA-256 / 9ac12f86ed2bdf9daa14ad21652b950416042113c3a7b8defcb381767563db9a

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(dest, chart):
    z = dest.strip()
    if len(z) == 10 and z[5] == '-' and z[6:].isdecimal():
        z = z[:5]
    if len(z) == 4 and z.isdecimal():
        z = z + '0'
    if len(z) != 5 or not z.isdecimal():
        return 'INVALID'
    p = int(z[:3])
    best = None
    for lo, hi, zone in chart:
        if lo <= p <= hi:
            if best is None or (hi - lo) < (best[1] - best[0]):
                best = (lo, hi, zone)
    return best[2] if best else 'NO_ZONE'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 4', ['10001-12a4', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 7', ['09999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 15', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5]], [['generated mix 75', ['0501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 17', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 25', ['15999-123', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 29', ['02134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 37', ['\t21000\n', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 2], ['generated mix 45', ['15999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4]], [['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['generated mix 40', ['00501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 48', ['10001', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 56', ['21499', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 2]]]
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 fixture	Actual	Expected	Outcome
lost leading zero	`2`	`8`	Failed
generated mix 38	`NO_ZONE`	`8`	Failed
zip plus four	`4`	`4`	Passed
nested narrowest	`6`	`6`	Passed
equal width higher zone first	`9`	`9`	Passed
letters	`INVALID`	`INVALID`	Passed
range upper edge	`5`	`5`	Passed
generated mix 4	`INVALID`	`INVALID`	Passed

SHA-256 / 78db7379bf6bc78b184991ddf5465d97fa4afdf3acf9d05e85f8267748621c7d

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(dest, chart):
    z = dest.strip()
    if len(z) == 10 and z[5] == '-' and z[6:].isdecimal():
        z = z[:5]
    if len(z) == 4 and z.isdecimal():
        z = '0' + z
    if len(z) != 5 or not z.isdecimal():
        return 'INVALID'
    p = int(z[:3])
    best = None
    for lo, hi, zone in chart:
        if lo <= p <= hi:
            if best is None or (hi - lo) < (best[1] - best[0]):
                best = (lo, hi, zone)
    return best[2] if best else 'NO_ZONE'
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 4', ['10001-12a4', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['generated mix 7', ['09999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 15', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5]], [['generated mix 75', ['0501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 17', ['16000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 25', ['15999-123', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID']], [['lost leading zero', ['2134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['zip plus four', ['15012-3456', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4], ['nested narrowest', ['21700', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 6], ['equal width higher zone first', ['21600', [[210, 219, 9], [215, 224, 2]]], 9], ['letters', ['123AB', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'INVALID'], ['generated mix 29', ['02134', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 37', ['\t21000\n', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 2], ['generated mix 45', ['15999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 4]], [['generated mix 38', ['9999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['range upper edge', ['19999', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['equal width first listed', ['21500', [[210, 219, 2], [215, 224, 9]]], 2], ['equal width plus four', ['21999-0001', [[200, 299, 1], [210, 219, 7], [215, 224, 3]]], 7], ['outside chart', ['40000', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 'NO_ZONE'], ['generated mix 40', ['00501', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 8], ['generated mix 48', ['10001', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 5], ['generated mix 56', ['21499', [[5, 99, 8], [100, 199, 5], [150, 159, 4], [200, 299, 3], [210, 219, 2], [215, 219, 6], [300, 399, 7]]], 2]]]
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 fixture	Actual	Expected	Outcome
lost leading zero	`8`	`8`	Passed
generated mix 38	`8`	`8`	Passed
zip plus four	`4`	`4`	Passed
nested narrowest	`6`	`6`	Passed
equal width higher zone first	`9`	`9`	Passed
letters	`INVALID`	`INVALID`	Passed
range upper edge	`5`	`5`	Passed
generated mix 4	`INVALID`	`INVALID`	Passed

SHA-256 / f9cb21aa6137a8e1f13c8e7a3bc4de8873ef0da8565ec39aecbf91779f981b4b

Verification & scope

Stipulated chart rows and input normalization; not a carrier-published chart. 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 2026-09-29T14:52:12.828596+00:00.

Case digest / 6edc272f162c58d5575866db7265ccfa6c51bad22252a2b63f7e665df6f68cdd