FA-59796 / Subscription proration billing / Open access
Renewal price with lock and increase cap: lock expiry day · case 01
Renewals on the lock expiry day lose the locked price.
ROOT CAUSE
The lock is treated as expired on its last valid day.
VERIFIED REPAIR
Restore the contract rule at the lock expiry day step: use `x['renewal_day'] <= x['lock_until']`.
Unsuccessful approach: The attempt honors the lock one day past its expiry.
Case contract
Input {last_paid, list_price, locked|None, lock_until, renewal_day, cap_pct}. While the lock is active (renewal_day <= lock_until) the target is min(list_price, locked); otherwise list_price. The renewal price is min(target, last_paid*(100+cap_pct)//100). Return cents.
Why this case matters
Grandfathered prices and increase caps protect renewing subscribers; their interplay sets the renewal amount.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(x):
if x['locked'] is not None and x['renewal_day'] < x['lock_until']:
target = min(x['list_price'], x['locked'])
else:
target = x['list_price']
ceiling = x['last_paid'] * (100 + x['cap_pct']) // 100
return min(target, ceiling)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression', {'last_paid': 6548, 'list_price': 6483, 'locked': 6448, 'lock_until': 196, 'renewal_day': 196, 'cap_pct': 5}, 6448), ('regression', {'last_paid': 2000, 'list_price': 3042, 'locked': 1900, 'lock_until': 55, 'renewal_day': 55, 'cap_pct': 5}, 1900), ('partial-repair probe', {'last_paid': 2000, 'list_price': 3442, 'locked': 2000, 'lock_until': 83, 'renewal_day': 84, 'cap_pct': 5}, 2100), ('partial-repair probe', {'last_paid': 2000, 'list_price': 4561, 'locked': 1900, 'lock_until': 96, 'renewal_day': 97, 'cap_pct': 20}, 2400), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1500, 'lock_until': 328, 'renewal_day': 201, 'cap_pct': 20}, 1000), ('normal control', {'last_paid': 2000, 'list_price': 3312, 'locked': 2500, 'lock_until': 173, 'renewal_day': 173, 'cap_pct': 20}, 2400), ('normal control', {'last_paid': 4900, 'list_price': 4900, 'locked': None, 'lock_until': 83, 'renewal_day': 100, 'cap_pct': 20}, 4900), ('normal control', {'last_paid': 222, 'list_price': 222, 'locked': 222, 'lock_until': 231, 'renewal_day': 231, 'cap_pct': 5}, 222)], [('regression', {'last_paid': 2000, 'list_price': 3042, 'locked': 1900, 'lock_until': 55, 'renewal_day': 55, 'cap_pct': 5}, 1900), ('regression', {'last_paid': 5437, 'list_price': 5507, 'locked': 5337, 'lock_until': 225, 'renewal_day': 225, 'cap_pct': 5}, 5337), ('partial-repair probe', {'last_paid': 4984, 'list_price': 7349, 'locked': 4984, 'lock_until': 94, 'renewal_day': 95, 'cap_pct': 20}, 5980), ('partial-repair probe', {'last_paid': 7649, 'list_price': 7649, 'locked': 7549, 'lock_until': 183, 'renewal_day': 184, 'cap_pct': 10}, 7649), ('normal control', {'last_paid': 4217, 'list_price': 4172, 'locked': 4217, 'lock_until': 1, 'renewal_day': 2, 'cap_pct': 0}, 4172), ('normal control', {'last_paid': 4900, 'list_price': 4441, 'locked': 4900, 'lock_until': 309, 'renewal_day': 310, 'cap_pct': 0}, 4441), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': 2000, 'lock_until': 91, 'renewal_day': 92, 'cap_pct': 5}, 2000), ('normal control', {'last_paid': 4900, 'list_price': 4900, 'locked': 4900, 'lock_until': 26, 'renewal_day': 27, 'cap_pct': 5}, 4900)], [('regression', {'last_paid': 5437, 'list_price': 5507, 'locked': 5337, 'lock_until': 225, 'renewal_day': 225, 'cap_pct': 5}, 5337), ('regression', {'last_paid': 2000, 'list_price': 3888, 'locked': 2000, 'lock_until': 333, 'renewal_day': 333, 'cap_pct': 10}, 2000), ('partial-repair probe', {'last_paid': 2000, 'list_price': 2000, 'locked': 1900, 'lock_until': 374, 'renewal_day': 375, 'cap_pct': 0}, 2000), ('partial-repair probe', {'last_paid': 4900, 'list_price': 5949, 'locked': 4900, 'lock_until': 379, 'renewal_day': 380, 'cap_pct': 10}, 5390), ('normal control', {'last_paid': 4900, 'list_price': 7407, 'locked': None, 'lock_until': 112, 'renewal_day': 113, 'cap_pct': 5}, 5145), ('normal control', {'last_paid': 485, 'list_price': 654, 'locked': None, 'lock_until': 58, 'renewal_day': 58, 'cap_pct': 20}, 582), ('normal control', {'last_paid': 1219, 'list_price': 1057, 'locked': 1119, 'lock_until': 293, 'renewal_day': 294, 'cap_pct': 10}, 1057), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1000, 'lock_until': 85, 'renewal_day': 85, 'cap_pct': 20}, 1000)], [('regression', {'last_paid': 2000, 'list_price': 3888, 'locked': 2000, 'lock_until': 333, 'renewal_day': 333, 'cap_pct': 10}, 2000), ('regression', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 392, 'renewal_day': 392, 'cap_pct': 5}, 900), ('partial-repair probe', {'last_paid': 7896, 'list_price': 8057, 'locked': 7896, 'lock_until': 71, 'renewal_day': 72, 'cap_pct': 20}, 8057), ('partial-repair probe', {'last_paid': 4900, 'list_price': 5888, 'locked': 5400, 'lock_until': 13, 'renewal_day': 14, 'cap_pct': 20}, 5880), ('normal control', {'last_paid': 2000, 'list_price': 3222, 'locked': 2500, 'lock_until': 57, 'renewal_day': 260, 'cap_pct': 0}, 2000), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1500, 'lock_until': 110, 'renewal_day': 262, 'cap_pct': 10}, 1000), ('normal control', {'last_paid': 7522, 'list_price': 7059, 'locked': 8022, 'lock_until': 19, 'renewal_day': 388, 'cap_pct': 20}, 7059), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': None, 'lock_until': 285, 'renewal_day': 285, 'cap_pct': 20}, 2000)], [('regression', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 392, 'renewal_day': 392, 'cap_pct': 5}, 900), ('regression', {'last_paid': 3101, 'list_price': 3101, 'locked': 3001, 'lock_until': 113, 'renewal_day': 113, 'cap_pct': 10}, 3001), ('partial-repair probe', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 109, 'renewal_day': 110, 'cap_pct': 5}, 1000), ('partial-repair probe', {'last_paid': 8551, 'list_price': 8551, 'locked': 8451, 'lock_until': 130, 'renewal_day': 131, 'cap_pct': 0}, 8551), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': None, 'lock_until': 173, 'renewal_day': 263, 'cap_pct': 5}, 2000), ('normal control', {'last_paid': 4105, 'list_price': 4394, 'locked': 4005, 'lock_until': 133, 'renewal_day': 322, 'cap_pct': 20}, 4394), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': 2500, 'lock_until': 167, 'renewal_day': 167, 'cap_pct': 10}, 2000), ('normal control', {'last_paid': 4900, 'list_price': 5180, 'locked': 4900, 'lock_until': 0, 'renewal_day': 66, 'cap_pct': 20}, 5180)]]
for i, (label, args, expected) in enumerate(fixtures[N-1]):
check("%s %d" % (label, i), 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 |
|---|---|---|---|
| regression 0 | 6483 | 6448 | Failed |
| regression 1 | 2100 | 1900 | Failed |
| partial-repair probe 2 | 2100 | 2100 | Passed |
| partial-repair probe 3 | 2400 | 2400 | Passed |
| normal control 4 | 1000 | 1000 | Passed |
| normal control 5 | 2400 | 2400 | Passed |
| normal control 6 | 4900 | 4900 | Passed |
| normal control 7 | 222 | 222 | Passed |
SHA-256 / 3024e28af4edf0ce484f5793799c65ba7bbf1522c792273043f1bbbf4c3e5eb3
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(x):
if x['locked'] is not None and x['renewal_day'] <= x['lock_until'] + 1:
target = min(x['list_price'], x['locked'])
else:
target = x['list_price']
ceiling = x['last_paid'] * (100 + x['cap_pct']) // 100
return min(target, ceiling)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression', {'last_paid': 6548, 'list_price': 6483, 'locked': 6448, 'lock_until': 196, 'renewal_day': 196, 'cap_pct': 5}, 6448), ('regression', {'last_paid': 2000, 'list_price': 3042, 'locked': 1900, 'lock_until': 55, 'renewal_day': 55, 'cap_pct': 5}, 1900), ('partial-repair probe', {'last_paid': 2000, 'list_price': 3442, 'locked': 2000, 'lock_until': 83, 'renewal_day': 84, 'cap_pct': 5}, 2100), ('partial-repair probe', {'last_paid': 2000, 'list_price': 4561, 'locked': 1900, 'lock_until': 96, 'renewal_day': 97, 'cap_pct': 20}, 2400), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1500, 'lock_until': 328, 'renewal_day': 201, 'cap_pct': 20}, 1000), ('normal control', {'last_paid': 2000, 'list_price': 3312, 'locked': 2500, 'lock_until': 173, 'renewal_day': 173, 'cap_pct': 20}, 2400), ('normal control', {'last_paid': 4900, 'list_price': 4900, 'locked': None, 'lock_until': 83, 'renewal_day': 100, 'cap_pct': 20}, 4900), ('normal control', {'last_paid': 222, 'list_price': 222, 'locked': 222, 'lock_until': 231, 'renewal_day': 231, 'cap_pct': 5}, 222)], [('regression', {'last_paid': 2000, 'list_price': 3042, 'locked': 1900, 'lock_until': 55, 'renewal_day': 55, 'cap_pct': 5}, 1900), ('regression', {'last_paid': 5437, 'list_price': 5507, 'locked': 5337, 'lock_until': 225, 'renewal_day': 225, 'cap_pct': 5}, 5337), ('partial-repair probe', {'last_paid': 4984, 'list_price': 7349, 'locked': 4984, 'lock_until': 94, 'renewal_day': 95, 'cap_pct': 20}, 5980), ('partial-repair probe', {'last_paid': 7649, 'list_price': 7649, 'locked': 7549, 'lock_until': 183, 'renewal_day': 184, 'cap_pct': 10}, 7649), ('normal control', {'last_paid': 4217, 'list_price': 4172, 'locked': 4217, 'lock_until': 1, 'renewal_day': 2, 'cap_pct': 0}, 4172), ('normal control', {'last_paid': 4900, 'list_price': 4441, 'locked': 4900, 'lock_until': 309, 'renewal_day': 310, 'cap_pct': 0}, 4441), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': 2000, 'lock_until': 91, 'renewal_day': 92, 'cap_pct': 5}, 2000), ('normal control', {'last_paid': 4900, 'list_price': 4900, 'locked': 4900, 'lock_until': 26, 'renewal_day': 27, 'cap_pct': 5}, 4900)], [('regression', {'last_paid': 5437, 'list_price': 5507, 'locked': 5337, 'lock_until': 225, 'renewal_day': 225, 'cap_pct': 5}, 5337), ('regression', {'last_paid': 2000, 'list_price': 3888, 'locked': 2000, 'lock_until': 333, 'renewal_day': 333, 'cap_pct': 10}, 2000), ('partial-repair probe', {'last_paid': 2000, 'list_price': 2000, 'locked': 1900, 'lock_until': 374, 'renewal_day': 375, 'cap_pct': 0}, 2000), ('partial-repair probe', {'last_paid': 4900, 'list_price': 5949, 'locked': 4900, 'lock_until': 379, 'renewal_day': 380, 'cap_pct': 10}, 5390), ('normal control', {'last_paid': 4900, 'list_price': 7407, 'locked': None, 'lock_until': 112, 'renewal_day': 113, 'cap_pct': 5}, 5145), ('normal control', {'last_paid': 485, 'list_price': 654, 'locked': None, 'lock_until': 58, 'renewal_day': 58, 'cap_pct': 20}, 582), ('normal control', {'last_paid': 1219, 'list_price': 1057, 'locked': 1119, 'lock_until': 293, 'renewal_day': 294, 'cap_pct': 10}, 1057), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1000, 'lock_until': 85, 'renewal_day': 85, 'cap_pct': 20}, 1000)], [('regression', {'last_paid': 2000, 'list_price': 3888, 'locked': 2000, 'lock_until': 333, 'renewal_day': 333, 'cap_pct': 10}, 2000), ('regression', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 392, 'renewal_day': 392, 'cap_pct': 5}, 900), ('partial-repair probe', {'last_paid': 7896, 'list_price': 8057, 'locked': 7896, 'lock_until': 71, 'renewal_day': 72, 'cap_pct': 20}, 8057), ('partial-repair probe', {'last_paid': 4900, 'list_price': 5888, 'locked': 5400, 'lock_until': 13, 'renewal_day': 14, 'cap_pct': 20}, 5880), ('normal control', {'last_paid': 2000, 'list_price': 3222, 'locked': 2500, 'lock_until': 57, 'renewal_day': 260, 'cap_pct': 0}, 2000), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1500, 'lock_until': 110, 'renewal_day': 262, 'cap_pct': 10}, 1000), ('normal control', {'last_paid': 7522, 'list_price': 7059, 'locked': 8022, 'lock_until': 19, 'renewal_day': 388, 'cap_pct': 20}, 7059), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': None, 'lock_until': 285, 'renewal_day': 285, 'cap_pct': 20}, 2000)], [('regression', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 392, 'renewal_day': 392, 'cap_pct': 5}, 900), ('regression', {'last_paid': 3101, 'list_price': 3101, 'locked': 3001, 'lock_until': 113, 'renewal_day': 113, 'cap_pct': 10}, 3001), ('partial-repair probe', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 109, 'renewal_day': 110, 'cap_pct': 5}, 1000), ('partial-repair probe', {'last_paid': 8551, 'list_price': 8551, 'locked': 8451, 'lock_until': 130, 'renewal_day': 131, 'cap_pct': 0}, 8551), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': None, 'lock_until': 173, 'renewal_day': 263, 'cap_pct': 5}, 2000), ('normal control', {'last_paid': 4105, 'list_price': 4394, 'locked': 4005, 'lock_until': 133, 'renewal_day': 322, 'cap_pct': 20}, 4394), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': 2500, 'lock_until': 167, 'renewal_day': 167, 'cap_pct': 10}, 2000), ('normal control', {'last_paid': 4900, 'list_price': 5180, 'locked': 4900, 'lock_until': 0, 'renewal_day': 66, 'cap_pct': 20}, 5180)]]
for i, (label, args, expected) in enumerate(fixtures[N-1]):
check("%s %d" % (label, i), 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 |
|---|---|---|---|
| regression 0 | 6448 | 6448 | Passed |
| regression 1 | 1900 | 1900 | Passed |
| partial-repair probe 2 | 2000 | 2100 | Failed |
| partial-repair probe 3 | 1900 | 2400 | Failed |
| normal control 4 | 1000 | 1000 | Passed |
| normal control 5 | 2400 | 2400 | Passed |
| normal control 6 | 4900 | 4900 | Passed |
| normal control 7 | 222 | 222 | Passed |
SHA-256 / c95dd8cde9780f60e915d3b5ab3a234039bd32108acc39f2d1e2e3791f4a92c2
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(x):
if x['locked'] is not None and x['renewal_day'] <= x['lock_until']:
target = min(x['list_price'], x['locked'])
else:
target = x['list_price']
ceiling = x['last_paid'] * (100 + x['cap_pct']) // 100
return min(target, ceiling)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression', {'last_paid': 6548, 'list_price': 6483, 'locked': 6448, 'lock_until': 196, 'renewal_day': 196, 'cap_pct': 5}, 6448), ('regression', {'last_paid': 2000, 'list_price': 3042, 'locked': 1900, 'lock_until': 55, 'renewal_day': 55, 'cap_pct': 5}, 1900), ('partial-repair probe', {'last_paid': 2000, 'list_price': 3442, 'locked': 2000, 'lock_until': 83, 'renewal_day': 84, 'cap_pct': 5}, 2100), ('partial-repair probe', {'last_paid': 2000, 'list_price': 4561, 'locked': 1900, 'lock_until': 96, 'renewal_day': 97, 'cap_pct': 20}, 2400), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1500, 'lock_until': 328, 'renewal_day': 201, 'cap_pct': 20}, 1000), ('normal control', {'last_paid': 2000, 'list_price': 3312, 'locked': 2500, 'lock_until': 173, 'renewal_day': 173, 'cap_pct': 20}, 2400), ('normal control', {'last_paid': 4900, 'list_price': 4900, 'locked': None, 'lock_until': 83, 'renewal_day': 100, 'cap_pct': 20}, 4900), ('normal control', {'last_paid': 222, 'list_price': 222, 'locked': 222, 'lock_until': 231, 'renewal_day': 231, 'cap_pct': 5}, 222)], [('regression', {'last_paid': 2000, 'list_price': 3042, 'locked': 1900, 'lock_until': 55, 'renewal_day': 55, 'cap_pct': 5}, 1900), ('regression', {'last_paid': 5437, 'list_price': 5507, 'locked': 5337, 'lock_until': 225, 'renewal_day': 225, 'cap_pct': 5}, 5337), ('partial-repair probe', {'last_paid': 4984, 'list_price': 7349, 'locked': 4984, 'lock_until': 94, 'renewal_day': 95, 'cap_pct': 20}, 5980), ('partial-repair probe', {'last_paid': 7649, 'list_price': 7649, 'locked': 7549, 'lock_until': 183, 'renewal_day': 184, 'cap_pct': 10}, 7649), ('normal control', {'last_paid': 4217, 'list_price': 4172, 'locked': 4217, 'lock_until': 1, 'renewal_day': 2, 'cap_pct': 0}, 4172), ('normal control', {'last_paid': 4900, 'list_price': 4441, 'locked': 4900, 'lock_until': 309, 'renewal_day': 310, 'cap_pct': 0}, 4441), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': 2000, 'lock_until': 91, 'renewal_day': 92, 'cap_pct': 5}, 2000), ('normal control', {'last_paid': 4900, 'list_price': 4900, 'locked': 4900, 'lock_until': 26, 'renewal_day': 27, 'cap_pct': 5}, 4900)], [('regression', {'last_paid': 5437, 'list_price': 5507, 'locked': 5337, 'lock_until': 225, 'renewal_day': 225, 'cap_pct': 5}, 5337), ('regression', {'last_paid': 2000, 'list_price': 3888, 'locked': 2000, 'lock_until': 333, 'renewal_day': 333, 'cap_pct': 10}, 2000), ('partial-repair probe', {'last_paid': 2000, 'list_price': 2000, 'locked': 1900, 'lock_until': 374, 'renewal_day': 375, 'cap_pct': 0}, 2000), ('partial-repair probe', {'last_paid': 4900, 'list_price': 5949, 'locked': 4900, 'lock_until': 379, 'renewal_day': 380, 'cap_pct': 10}, 5390), ('normal control', {'last_paid': 4900, 'list_price': 7407, 'locked': None, 'lock_until': 112, 'renewal_day': 113, 'cap_pct': 5}, 5145), ('normal control', {'last_paid': 485, 'list_price': 654, 'locked': None, 'lock_until': 58, 'renewal_day': 58, 'cap_pct': 20}, 582), ('normal control', {'last_paid': 1219, 'list_price': 1057, 'locked': 1119, 'lock_until': 293, 'renewal_day': 294, 'cap_pct': 10}, 1057), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1000, 'lock_until': 85, 'renewal_day': 85, 'cap_pct': 20}, 1000)], [('regression', {'last_paid': 2000, 'list_price': 3888, 'locked': 2000, 'lock_until': 333, 'renewal_day': 333, 'cap_pct': 10}, 2000), ('regression', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 392, 'renewal_day': 392, 'cap_pct': 5}, 900), ('partial-repair probe', {'last_paid': 7896, 'list_price': 8057, 'locked': 7896, 'lock_until': 71, 'renewal_day': 72, 'cap_pct': 20}, 8057), ('partial-repair probe', {'last_paid': 4900, 'list_price': 5888, 'locked': 5400, 'lock_until': 13, 'renewal_day': 14, 'cap_pct': 20}, 5880), ('normal control', {'last_paid': 2000, 'list_price': 3222, 'locked': 2500, 'lock_until': 57, 'renewal_day': 260, 'cap_pct': 0}, 2000), ('normal control', {'last_paid': 1000, 'list_price': 1000, 'locked': 1500, 'lock_until': 110, 'renewal_day': 262, 'cap_pct': 10}, 1000), ('normal control', {'last_paid': 7522, 'list_price': 7059, 'locked': 8022, 'lock_until': 19, 'renewal_day': 388, 'cap_pct': 20}, 7059), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': None, 'lock_until': 285, 'renewal_day': 285, 'cap_pct': 20}, 2000)], [('regression', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 392, 'renewal_day': 392, 'cap_pct': 5}, 900), ('regression', {'last_paid': 3101, 'list_price': 3101, 'locked': 3001, 'lock_until': 113, 'renewal_day': 113, 'cap_pct': 10}, 3001), ('partial-repair probe', {'last_paid': 1000, 'list_price': 1000, 'locked': 900, 'lock_until': 109, 'renewal_day': 110, 'cap_pct': 5}, 1000), ('partial-repair probe', {'last_paid': 8551, 'list_price': 8551, 'locked': 8451, 'lock_until': 130, 'renewal_day': 131, 'cap_pct': 0}, 8551), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': None, 'lock_until': 173, 'renewal_day': 263, 'cap_pct': 5}, 2000), ('normal control', {'last_paid': 4105, 'list_price': 4394, 'locked': 4005, 'lock_until': 133, 'renewal_day': 322, 'cap_pct': 20}, 4394), ('normal control', {'last_paid': 2000, 'list_price': 2000, 'locked': 2500, 'lock_until': 167, 'renewal_day': 167, 'cap_pct': 10}, 2000), ('normal control', {'last_paid': 4900, 'list_price': 5180, 'locked': 4900, 'lock_until': 0, 'renewal_day': 66, 'cap_pct': 20}, 5180)]]
for i, (label, args, expected) in enumerate(fixtures[N-1]):
check("%s %d" % (label, i), 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 |
|---|---|---|---|
| regression 0 | 6448 | 6448 | Passed |
| regression 1 | 1900 | 1900 | Passed |
| partial-repair probe 2 | 2100 | 2100 | Passed |
| partial-repair probe 3 | 2400 | 2400 | Passed |
| normal control 4 | 1000 | 1000 | Passed |
| normal control 5 | 2400 | 2400 | Passed |
| normal control 6 | 4900 | 4900 | Passed |
| normal control 7 | 222 | 222 | Passed |
SHA-256 / b51db86e6a04d4d81a1a9f1cfce0f9c68fd5f3c308f9b4884a32186a1f14b4d5
Verification & scope
A deterministic teaching model of a stipulated billing rule. It makes no claim to reproduce any billing provider's exact behaviour and is not billing software. 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 2026-09-29T14:46:39.628223+00:00.
Case digest / 5b11dde33fd966c33e24e745dfe3fefbc7b1f83b3f6d78950bc3198c5fa28877