FA-59761 / Subscription proration billing / Open access

Expiring credit grants applied to invoices: consumption order · case 01

Long-lived credits are consumed while short-lived ones expire unused.

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

ROOT CAUSE

Grants are consumed oldest-granted first instead of soonest-expiring first.

VERIFIED REPAIR

Restore the contract rule at the consumption order step: use `usable.sort(key=lambda g: (g[1], g[2]))`.

Unsuccessful approach: The attempt sorts by expiry descending.

Case contract

Input {grants: [[amount, expires_day, granted_day]], day, amount}. A grant is usable when granted_day <= day < expires_day. Usable grants are consumed soonest-expiring first (ties by earlier grant day, then input order). Return [applied, remaining_due, [[left, expires] for partially used or untouched usable grants]].

Why this case matters

Promotional credits must be burned in expiry order and never after they expire.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(x):
    usable = [g for g in x['grants'] if g[2] <= x['day'] < g[1]]
    usable.sort(key=lambda g: g[2])
    need = x['amount']
    applied = 0
    rest = []
    for amt, exp, gd in usable:
        take = min(amt, need)
        need -= take
        applied += take
        if amt - take > 0:
            rest.append([amt - take, exp])
    return [applied, need, rest]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression', {'grants': [[3819, 68, 16], [1930, 58, 26], [323, 59, 3], [2345, 29, 23], [2715, 44, 13]], 'day': 44, 'amount': 5792}, [5792, 0, [[280, 68]]]), ('regression', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('partial-repair probe', {'grants': [[2834, 10, 2], [2391, 78, 31], [4168, 56, 2], [1900, 63, 18], [3824, 30, 11]], 'day': 30, 'amount': 236}, [236, 0, [[3932, 56], [1900, 63]]]), ('partial-repair probe', {'grants': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('normal control', {'grants': [[1468, 59, 37], [2753, 34, 1], [3215, 49, 24]], 'day': 24, 'amount': 9315}, [5968, 3347, []]), ('normal control', {'grants': [[2342, 62, 27], [2349, 64, 11], [3400, 5, 3], [4319, 29, 10]], 'day': 3, 'amount': 11699}, [3400, 8299, []]), ('normal control', {'grants': [[2784, 49, 29], [4250, 5, 2]], 'day': 5, 'amount': 6418}, [0, 6418, []]), ('normal control', {'grants': [[2773, 15, 9], [1310, 48, 23], [4052, 71, 20]], 'day': 23, 'amount': 8492}, [5362, 3130, []])], [('regression', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('regression', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('partial-repair probe', {'grants': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('partial-repair probe', {'grants': [[3527, 52, 33], [1461, 57, 34], [978, 47, 40], [4380, 48, 0]], 'day': 34, 'amount': 7979}, [7979, 0, [[1389, 57]]]), ('normal control', {'grants': [[1384, 70, 15], [4042, 35, 28], [3777, 37, 32], [3126, 48, 5]], 'day': 28, 'amount': 10480}, [8552, 1928, []]), ('normal control', {'grants': [[2817, 40, 9], [519, 18, 4], [2025, 35, 27]], 'day': 18, 'amount': 2988}, [2817, 171, []]), ('normal control', {'grants': [[4886, 68, 27]], 'day': 34, 'amount': 6459}, [4886, 1573, []]), ('normal control', {'grants': [[4933, 63, 40]], 'day': 63, 'amount': 7306}, [0, 7306, []])], [('regression', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('regression', {'grants': [[402, 28, 2], [4255, 65, 36], [2572, 56, 6], [4531, 25, 19], [2694, 48, 28]], 'day': 36, 'amount': 3121}, [3121, 0, [[2145, 56], [4255, 65]]]), ('partial-repair probe', {'grants': [[571, 50, 17], [4761, 10, 6], [3521, 82, 34], [1414, 36, 2]], 'day': 34, 'amount': 721}, [721, 0, [[693, 36], [571, 50], [3521, 82]]]), ('partial-repair probe', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('normal control', {'grants': [[348, 44, 22], [3151, 71, 29], [1829, 75, 25]], 'day': 22, 'amount': 1836}, [348, 1488, []]), ('normal control', {'grants': [[4428, 38, 34], [4352, 38, 5], [1603, 11, 10]], 'day': 38, 'amount': 11185}, [0, 11185, []]), ('normal control', {'grants': [[1532, 36, 16], [3167, 81, 23]], 'day': 79, 'amount': 9179}, [3167, 6012, []]), ('normal control', {'grants': [[1721, 49, 40], [1723, 56, 3], [735, 16, 1]], 'day': 56, 'amount': 7084}, [0, 7084, []])], [('regression', {'grants': [[402, 28, 2], [4255, 65, 36], [2572, 56, 6], [4531, 25, 19], [2694, 48, 28]], 'day': 36, 'amount': 3121}, [3121, 0, [[2145, 56], [4255, 65]]]), ('regression', {'grants': [[3489, 77, 37], [4072, 62, 23], [470, 62, 5], [2073, 40, 29], [1072, 34, 0]], 'day': 29, 'amount': 5684}, [5684, 0, [[2003, 62]]]), ('partial-repair probe', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('partial-repair probe', {'grants': [[3812, 65, 19], [1707, 52, 18], [3211, 41, 24], [3775, 75, 29], [2654, 22, 1]], 'day': 41, 'amount': 6841}, [6841, 0, [[2453, 75]]]), ('normal control', {'grants': [], 'day': 33, 'amount': 11076}, [0, 11076, []]), ('normal control', {'grants': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('normal control', {'grants': [[1110, 34, 23], [3403, 54, 35], [4357, 61, 21], [1009, 33, 4], [1988, 42, 17]], 'day': 33, 'amount': 7737}, [7455, 282, []]), ('normal control', {'grants': [], 'day': 50, 'amount': 6225}, [0, 6225, []])], [('regression', {'grants': [[3489, 77, 37], [4072, 62, 23], [470, 62, 5], [2073, 40, 29], [1072, 34, 0]], 'day': 29, 'amount': 5684}, [5684, 0, [[2003, 62]]]), ('regression', {'grants': [[3971, 27, 11], [4895, 40, 6], [3338, 81, 23], [122, 78, 29], [4523, 78, 24]], 'day': 29, 'amount': 7395}, [7395, 0, [[2023, 78], [122, 78], [3338, 81]]]), ('partial-repair probe', {'grants': [[3812, 65, 19], [1707, 52, 18], [3211, 41, 24], [3775, 75, 29], [2654, 22, 1]], 'day': 41, 'amount': 6841}, [6841, 0, [[2453, 75]]]), ('partial-repair probe', {'grants': [[4874, 70, 33], [4203, 58, 8]], 'day': 33, 'amount': 972}, [972, 0, [[3231, 58], [4874, 70]]]), ('normal control', {'grants': [[3265, 3, 2], [961, 90, 30], [2437, 40, 28]], 'day': 3, 'amount': 6149}, [0, 6149, []]), ('normal control', {'grants': [[1585, 58, 15], [4019, 40, 15], [2113, 83, 26]], 'day': 83, 'amount': 3346}, [0, 3346, []]), ('normal control', {'grants': [[1988, 63, 35]], 'day': 58, 'amount': 4262}, [1988, 2274, []]), ('normal control', {'grants': [[1288, 33, 20]], 'day': 20, 'amount': 7312}, [1288, 6024, []])]]
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	`[5792, 0, [[280, 58]]]`	`[5792, 0, [[280, 68]]]`	Failed
regression 1	`[3058, 0, [[733, 45], [4651, 53], [3113, 56]]]`	`[3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]`	Failed
partial-repair probe 2	`[236, 0, [[3932, 56], [1900, 63]]]`	`[236, 0, [[3932, 56], [1900, 63]]]`	Passed
partial-repair probe 3	`[2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]`	`[2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]`	Passed
normal control 4	`[5968, 3347, []]`	`[5968, 3347, []]`	Passed
normal control 5	`[3400, 8299, []]`	`[3400, 8299, []]`	Passed
normal control 6	`[0, 6418, []]`	`[0, 6418, []]`	Passed
normal control 7	`[5362, 3130, []]`	`[5362, 3130, []]`	Passed

SHA-256 / 3ef63e6593f8c4e1fe6aa75d32673e9104100d669ad3f204e7d908a126892df3

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(x):
    usable = [g for g in x['grants'] if g[2] <= x['day'] < g[1]]
    usable.sort(key=lambda g: (-g[1], g[2]))
    need = x['amount']
    applied = 0
    rest = []
    for amt, exp, gd in usable:
        take = min(amt, need)
        need -= take
        applied += take
        if amt - take > 0:
            rest.append([amt - take, exp])
    return [applied, need, rest]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression', {'grants': [[3819, 68, 16], [1930, 58, 26], [323, 59, 3], [2345, 29, 23], [2715, 44, 13]], 'day': 44, 'amount': 5792}, [5792, 0, [[280, 68]]]), ('regression', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('partial-repair probe', {'grants': [[2834, 10, 2], [2391, 78, 31], [4168, 56, 2], [1900, 63, 18], [3824, 30, 11]], 'day': 30, 'amount': 236}, [236, 0, [[3932, 56], [1900, 63]]]), ('partial-repair probe', {'grants': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('normal control', {'grants': [[1468, 59, 37], [2753, 34, 1], [3215, 49, 24]], 'day': 24, 'amount': 9315}, [5968, 3347, []]), ('normal control', {'grants': [[2342, 62, 27], [2349, 64, 11], [3400, 5, 3], [4319, 29, 10]], 'day': 3, 'amount': 11699}, [3400, 8299, []]), ('normal control', {'grants': [[2784, 49, 29], [4250, 5, 2]], 'day': 5, 'amount': 6418}, [0, 6418, []]), ('normal control', {'grants': [[2773, 15, 9], [1310, 48, 23], [4052, 71, 20]], 'day': 23, 'amount': 8492}, [5362, 3130, []])], [('regression', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('regression', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('partial-repair probe', {'grants': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('partial-repair probe', {'grants': [[3527, 52, 33], [1461, 57, 34], [978, 47, 40], [4380, 48, 0]], 'day': 34, 'amount': 7979}, [7979, 0, [[1389, 57]]]), ('normal control', {'grants': [[1384, 70, 15], [4042, 35, 28], [3777, 37, 32], [3126, 48, 5]], 'day': 28, 'amount': 10480}, [8552, 1928, []]), ('normal control', {'grants': [[2817, 40, 9], [519, 18, 4], [2025, 35, 27]], 'day': 18, 'amount': 2988}, [2817, 171, []]), ('normal control', {'grants': [[4886, 68, 27]], 'day': 34, 'amount': 6459}, [4886, 1573, []]), ('normal control', {'grants': [[4933, 63, 40]], 'day': 63, 'amount': 7306}, [0, 7306, []])], [('regression', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('regression', {'grants': [[402, 28, 2], [4255, 65, 36], [2572, 56, 6], [4531, 25, 19], [2694, 48, 28]], 'day': 36, 'amount': 3121}, [3121, 0, [[2145, 56], [4255, 65]]]), ('partial-repair probe', {'grants': [[571, 50, 17], [4761, 10, 6], [3521, 82, 34], [1414, 36, 2]], 'day': 34, 'amount': 721}, [721, 0, [[693, 36], [571, 50], [3521, 82]]]), ('partial-repair probe', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('normal control', {'grants': [[348, 44, 22], [3151, 71, 29], [1829, 75, 25]], 'day': 22, 'amount': 1836}, [348, 1488, []]), ('normal control', {'grants': [[4428, 38, 34], [4352, 38, 5], [1603, 11, 10]], 'day': 38, 'amount': 11185}, [0, 11185, []]), ('normal control', {'grants': [[1532, 36, 16], [3167, 81, 23]], 'day': 79, 'amount': 9179}, [3167, 6012, []]), ('normal control', {'grants': [[1721, 49, 40], [1723, 56, 3], [735, 16, 1]], 'day': 56, 'amount': 7084}, [0, 7084, []])], [('regression', {'grants': [[402, 28, 2], [4255, 65, 36], [2572, 56, 6], [4531, 25, 19], [2694, 48, 28]], 'day': 36, 'amount': 3121}, [3121, 0, [[2145, 56], [4255, 65]]]), ('regression', {'grants': [[3489, 77, 37], [4072, 62, 23], [470, 62, 5], [2073, 40, 29], [1072, 34, 0]], 'day': 29, 'amount': 5684}, [5684, 0, [[2003, 62]]]), ('partial-repair probe', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('partial-repair probe', {'grants': [[3812, 65, 19], [1707, 52, 18], [3211, 41, 24], [3775, 75, 29], [2654, 22, 1]], 'day': 41, 'amount': 6841}, [6841, 0, [[2453, 75]]]), ('normal control', {'grants': [], 'day': 33, 'amount': 11076}, [0, 11076, []]), ('normal control', {'grants': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('normal control', {'grants': [[1110, 34, 23], [3403, 54, 35], [4357, 61, 21], [1009, 33, 4], [1988, 42, 17]], 'day': 33, 'amount': 7737}, [7455, 282, []]), ('normal control', {'grants': [], 'day': 50, 'amount': 6225}, [0, 6225, []])], [('regression', {'grants': [[3489, 77, 37], [4072, 62, 23], [470, 62, 5], [2073, 40, 29], [1072, 34, 0]], 'day': 29, 'amount': 5684}, [5684, 0, [[2003, 62]]]), ('regression', {'grants': [[3971, 27, 11], [4895, 40, 6], [3338, 81, 23], [122, 78, 29], [4523, 78, 24]], 'day': 29, 'amount': 7395}, [7395, 0, [[2023, 78], [122, 78], [3338, 81]]]), ('partial-repair probe', {'grants': [[3812, 65, 19], [1707, 52, 18], [3211, 41, 24], [3775, 75, 29], [2654, 22, 1]], 'day': 41, 'amount': 6841}, [6841, 0, [[2453, 75]]]), ('partial-repair probe', {'grants': [[4874, 70, 33], [4203, 58, 8]], 'day': 33, 'amount': 972}, [972, 0, [[3231, 58], [4874, 70]]]), ('normal control', {'grants': [[3265, 3, 2], [961, 90, 30], [2437, 40, 28]], 'day': 3, 'amount': 6149}, [0, 6149, []]), ('normal control', {'grants': [[1585, 58, 15], [4019, 40, 15], [2113, 83, 26]], 'day': 83, 'amount': 3346}, [0, 3346, []]), ('normal control', {'grants': [[1988, 63, 35]], 'day': 58, 'amount': 4262}, [1988, 2274, []]), ('normal control', {'grants': [[1288, 33, 20]], 'day': 20, 'amount': 7312}, [1288, 6024, []])]]
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	`[5792, 0, [[280, 58]]]`	`[5792, 0, [[280, 68]]]`	Failed
regression 1	`[3058, 0, [[185, 56], [4651, 53], [3661, 45]]]`	`[3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]`	Failed
partial-repair probe 2	`[236, 0, [[1664, 63], [4168, 56]]]`	`[236, 0, [[3932, 56], [1900, 63]]]`	Failed
partial-repair probe 3	`[2567, 0, [[1085, 78], [3344, 61], [3775, 47]]]`	`[2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]`	Failed
normal control 4	`[5968, 3347, []]`	`[5968, 3347, []]`	Passed
normal control 5	`[3400, 8299, []]`	`[3400, 8299, []]`	Passed
normal control 6	`[0, 6418, []]`	`[0, 6418, []]`	Passed
normal control 7	`[5362, 3130, []]`	`[5362, 3130, []]`	Passed

SHA-256 / 2d0a24cf9ae1dfcfcbac3cbd8ad524f5b154a9dcb3f0f3bcb6d90e746710d875

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(x):
    usable = [g for g in x['grants'] if g[2] <= x['day'] < g[1]]
    usable.sort(key=lambda g: (g[1], g[2]))
    need = x['amount']
    applied = 0
    rest = []
    for amt, exp, gd in usable:
        take = min(amt, need)
        need -= take
        applied += take
        if amt - take > 0:
            rest.append([amt - take, exp])
    return [applied, need, rest]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression', {'grants': [[3819, 68, 16], [1930, 58, 26], [323, 59, 3], [2345, 29, 23], [2715, 44, 13]], 'day': 44, 'amount': 5792}, [5792, 0, [[280, 68]]]), ('regression', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('partial-repair probe', {'grants': [[2834, 10, 2], [2391, 78, 31], [4168, 56, 2], [1900, 63, 18], [3824, 30, 11]], 'day': 30, 'amount': 236}, [236, 0, [[3932, 56], [1900, 63]]]), ('partial-repair probe', {'grants': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('normal control', {'grants': [[1468, 59, 37], [2753, 34, 1], [3215, 49, 24]], 'day': 24, 'amount': 9315}, [5968, 3347, []]), ('normal control', {'grants': [[2342, 62, 27], [2349, 64, 11], [3400, 5, 3], [4319, 29, 10]], 'day': 3, 'amount': 11699}, [3400, 8299, []]), ('normal control', {'grants': [[2784, 49, 29], [4250, 5, 2]], 'day': 5, 'amount': 6418}, [0, 6418, []]), ('normal control', {'grants': [[2773, 15, 9], [1310, 48, 23], [4052, 71, 20]], 'day': 23, 'amount': 8492}, [5362, 3130, []])], [('regression', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('regression', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('partial-repair probe', {'grants': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('partial-repair probe', {'grants': [[3527, 52, 33], [1461, 57, 34], [978, 47, 40], [4380, 48, 0]], 'day': 34, 'amount': 7979}, [7979, 0, [[1389, 57]]]), ('normal control', {'grants': [[1384, 70, 15], [4042, 35, 28], [3777, 37, 32], [3126, 48, 5]], 'day': 28, 'amount': 10480}, [8552, 1928, []]), ('normal control', {'grants': [[2817, 40, 9], [519, 18, 4], [2025, 35, 27]], 'day': 18, 'amount': 2988}, [2817, 171, []]), ('normal control', {'grants': [[4886, 68, 27]], 'day': 34, 'amount': 6459}, [4886, 1573, []]), ('normal control', {'grants': [[4933, 63, 40]], 'day': 63, 'amount': 7306}, [0, 7306, []])], [('regression', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('regression', {'grants': [[402, 28, 2], [4255, 65, 36], [2572, 56, 6], [4531, 25, 19], [2694, 48, 28]], 'day': 36, 'amount': 3121}, [3121, 0, [[2145, 56], [4255, 65]]]), ('partial-repair probe', {'grants': [[571, 50, 17], [4761, 10, 6], [3521, 82, 34], [1414, 36, 2]], 'day': 34, 'amount': 721}, [721, 0, [[693, 36], [571, 50], [3521, 82]]]), ('partial-repair probe', {'grants': [[4651, 53, 31], [3113, 56, 35], [1383, 36, 23], [3661, 45, 24], [130, 62, 8]], 'day': 36, 'amount': 3058}, [3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]), ('normal control', {'grants': [[348, 44, 22], [3151, 71, 29], [1829, 75, 25]], 'day': 22, 'amount': 1836}, [348, 1488, []]), ('normal control', {'grants': [[4428, 38, 34], [4352, 38, 5], [1603, 11, 10]], 'day': 38, 'amount': 11185}, [0, 11185, []]), ('normal control', {'grants': [[1532, 36, 16], [3167, 81, 23]], 'day': 79, 'amount': 9179}, [3167, 6012, []]), ('normal control', {'grants': [[1721, 49, 40], [1723, 56, 3], [735, 16, 1]], 'day': 56, 'amount': 7084}, [0, 7084, []])], [('regression', {'grants': [[402, 28, 2], [4255, 65, 36], [2572, 56, 6], [4531, 25, 19], [2694, 48, 28]], 'day': 36, 'amount': 3121}, [3121, 0, [[2145, 56], [4255, 65]]]), ('regression', {'grants': [[3489, 77, 37], [4072, 62, 23], [470, 62, 5], [2073, 40, 29], [1072, 34, 0]], 'day': 29, 'amount': 5684}, [5684, 0, [[2003, 62]]]), ('partial-repair probe', {'grants': [[1398, 69, 19], [4543, 47, 36], [2876, 44, 37], [4466, 58, 16]], 'day': 37, 'amount': 1446}, [1446, 0, [[1430, 44], [4543, 47], [4466, 58], [1398, 69]]]), ('partial-repair probe', {'grants': [[3812, 65, 19], [1707, 52, 18], [3211, 41, 24], [3775, 75, 29], [2654, 22, 1]], 'day': 41, 'amount': 6841}, [6841, 0, [[2453, 75]]]), ('normal control', {'grants': [], 'day': 33, 'amount': 11076}, [0, 11076, []]), ('normal control', {'grants': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('normal control', {'grants': [[1110, 34, 23], [3403, 54, 35], [4357, 61, 21], [1009, 33, 4], [1988, 42, 17]], 'day': 33, 'amount': 7737}, [7455, 282, []]), ('normal control', {'grants': [], 'day': 50, 'amount': 6225}, [0, 6225, []])], [('regression', {'grants': [[3489, 77, 37], [4072, 62, 23], [470, 62, 5], [2073, 40, 29], [1072, 34, 0]], 'day': 29, 'amount': 5684}, [5684, 0, [[2003, 62]]]), ('regression', {'grants': [[3971, 27, 11], [4895, 40, 6], [3338, 81, 23], [122, 78, 29], [4523, 78, 24]], 'day': 29, 'amount': 7395}, [7395, 0, [[2023, 78], [122, 78], [3338, 81]]]), ('partial-repair probe', {'grants': [[3812, 65, 19], [1707, 52, 18], [3211, 41, 24], [3775, 75, 29], [2654, 22, 1]], 'day': 41, 'amount': 6841}, [6841, 0, [[2453, 75]]]), ('partial-repair probe', {'grants': [[4874, 70, 33], [4203, 58, 8]], 'day': 33, 'amount': 972}, [972, 0, [[3231, 58], [4874, 70]]]), ('normal control', {'grants': [[3265, 3, 2], [961, 90, 30], [2437, 40, 28]], 'day': 3, 'amount': 6149}, [0, 6149, []]), ('normal control', {'grants': [[1585, 58, 15], [4019, 40, 15], [2113, 83, 26]], 'day': 83, 'amount': 3346}, [0, 3346, []]), ('normal control', {'grants': [[1988, 63, 35]], 'day': 58, 'amount': 4262}, [1988, 2274, []]), ('normal control', {'grants': [[1288, 33, 20]], 'day': 20, 'amount': 7312}, [1288, 6024, []])]]
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	`[5792, 0, [[280, 68]]]`	`[5792, 0, [[280, 68]]]`	Passed
regression 1	`[3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]`	`[3058, 0, [[603, 45], [4651, 53], [3113, 56], [130, 62]]]`	Passed
partial-repair probe 2	`[236, 0, [[3932, 56], [1900, 63]]]`	`[236, 0, [[3932, 56], [1900, 63]]]`	Passed
partial-repair probe 3	`[2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]`	`[2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]`	Passed
normal control 4	`[5968, 3347, []]`	`[5968, 3347, []]`	Passed
normal control 5	`[3400, 8299, []]`	`[3400, 8299, []]`	Passed
normal control 6	`[0, 6418, []]`	`[0, 6418, []]`	Passed
normal control 7	`[5362, 3130, []]`	`[5362, 3130, []]`	Passed

SHA-256 / 266f12891f9eb98193e209e171e73ebd713c3712aa50a10035a83fe57648a0f0

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 2026-09-29T14:46:39.391356+00:00.

Case digest / d7837890d9c09e6656c55480c3f46b4bee006f25177ec2e03754231596ff80f7