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FA-59766 / Subscription proration billing / Open access

Expiring credit grants applied to invoices: partial grant remainder · case 01

Partially used credits reappear at full value.

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

ROOT CAUSE

The remaining list reports the original grant amount.

VERIFIED REPAIR

Restore the contract rule at the partial grant remainder step: use `if amt - take > 0: rest.append([amt - take, exp])`.

Unsuccessful approach: The attempt lists only untouched grants, losing partially used ones.

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[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, 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': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('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': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('regression', {'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]]]), ('partial-repair probe', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [[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]]]), ('regression', {'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': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [[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': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('regression', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [], 'day': 33, 'amount': 11076}, [0, 11076, []]), ('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, []]), ('normal control', {'grants': [[3265, 3, 2], [961, 90, 30], [2437, 40, 28]], 'day': 3, 'amount': 6149}, [0, 6149, []])], [('regression', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('regression', {'grants': [[3527, 52, 33], [1461, 57, 34], [978, 47, 40], [4380, 48, 0]], 'day': 34, 'amount': 7979}, [7979, 0, [[1389, 57]]]), ('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': [[1738, 62, 14], [2402, 54, 26]], 'day': 14, 'amount': 1718}, [1718, 0, [[20, 62]]]), ('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, []]), ('normal control', {'grants': [[324, 48, 13], [3431, 60, 6], [301, 29, 1], [1437, 59, 27]], 'day': 29, 'amount': 8166}, [5192, 2974, []])]]
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 fixtureActualExpectedOutcome
regression 0[5792, 0, [[3819, 68]]][5792, 0, [[280, 68]]]Failed
regression 1[1147, 0, [[4520, 73]]][1147, 0, [[3373, 73]]]Failed
partial-repair probe 2[236, 0, [[4168, 56], [1900, 63]]][236, 0, [[3932, 56], [1900, 63]]]Failed
partial-repair probe 3[2567, 0, [[3775, 47], [3344, 61], [3652, 78]]][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 / fb7f82c2b1c72426015b922b23a606b18fbf7264228485fbc7e275b1d091facf

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 take == 0:
            rest.append([amt, 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': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('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': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('regression', {'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]]]), ('partial-repair probe', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [[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]]]), ('regression', {'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': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [[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': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('regression', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [], 'day': 33, 'amount': 11076}, [0, 11076, []]), ('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, []]), ('normal control', {'grants': [[3265, 3, 2], [961, 90, 30], [2437, 40, 28]], 'day': 3, 'amount': 6149}, [0, 6149, []])], [('regression', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('regression', {'grants': [[3527, 52, 33], [1461, 57, 34], [978, 47, 40], [4380, 48, 0]], 'day': 34, 'amount': 7979}, [7979, 0, [[1389, 57]]]), ('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': [[1738, 62, 14], [2402, 54, 26]], 'day': 14, 'amount': 1718}, [1718, 0, [[20, 62]]]), ('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, []]), ('normal control', {'grants': [[324, 48, 13], [3431, 60, 6], [301, 29, 1], [1437, 59, 27]], 'day': 29, 'amount': 8166}, [5192, 2974, []])]]
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 fixtureActualExpectedOutcome
regression 0[5792, 0, []][5792, 0, [[280, 68]]]Failed
regression 1[1147, 0, []][1147, 0, [[3373, 73]]]Failed
partial-repair probe 2[236, 0, [[1900, 63]]][236, 0, [[3932, 56], [1900, 63]]]Failed
partial-repair probe 3[2567, 0, [[3344, 61], [3652, 78]]][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 / 2b6336fcc2529f89ceb5c788e6c47136cdb649ad6edcf21d65166201956fd3c1

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': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('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': [[3257, 40, 31], [4520, 73, 40], [4293, 11, 10]], 'day': 40, 'amount': 1147}, [1147, 0, [[3373, 73]]]), ('regression', {'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]]]), ('partial-repair probe', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [[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]]]), ('regression', {'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': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [[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': [[3652, 78, 36], [3344, 61, 28], [3775, 47, 19]], 'day': 36, 'amount': 2567}, [2567, 0, [[1208, 47], [3344, 61], [3652, 78]]]), ('regression', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('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': [], 'day': 33, 'amount': 11076}, [0, 11076, []]), ('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, []]), ('normal control', {'grants': [[3265, 3, 2], [961, 90, 30], [2437, 40, 28]], 'day': 3, 'amount': 6149}, [0, 6149, []])], [('regression', {'grants': [[4546, 83, 40], [460, 75, 40], [4086, 56, 18], [3942, 30, 22]], 'day': 30, 'amount': 3239}, [3239, 0, [[847, 56]]]), ('regression', {'grants': [[3527, 52, 33], [1461, 57, 34], [978, 47, 40], [4380, 48, 0]], 'day': 34, 'amount': 7979}, [7979, 0, [[1389, 57]]]), ('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': [[1738, 62, 14], [2402, 54, 26]], 'day': 14, 'amount': 1718}, [1718, 0, [[20, 62]]]), ('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, []]), ('normal control', {'grants': [[324, 48, 13], [3431, 60, 6], [301, 29, 1], [1437, 59, 27]], 'day': 29, 'amount': 8166}, [5192, 2974, []])]]
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 fixtureActualExpectedOutcome
regression 0[5792, 0, [[280, 68]]][5792, 0, [[280, 68]]]Passed
regression 1[1147, 0, [[3373, 73]]][1147, 0, [[3373, 73]]]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 / 07c48729bb0c4afda4da8765a693cacf498f5f1fbe85dcc51e4946e3c75109f2

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 2026-09-29T14:46:39.440034+00:00.

Case digest / db5a20e4c5bc3b3240d016a7ec9d61e1cbb9c1b57c932cbad7e8eae5659e44a2