FA-60246 / Inventory cost layering / Open access

Layer aging and slow-moving reserve: overflow bucket · case 01

Stock older than the last bound is merged into the last bucket and reserved at its lower rate.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The bucket search stops one bucket early, never reaching the overflow bucket.

VERIFIED REPAIR

Search all bounds so ages past the last bound land in the overflow bucket.

Unsuccessful approach: Only routing ages above one year to the overflow still misplaces moderately old stock.

Case contract

Input {layers:[[receipt_day,qty,unit]], today, buckets:[upper age bounds, inclusive], reserve_bp:[rate per bucket incl. overflow]}. Age = today - receipt_day; layers with negative age are in transit and excluded. A layer falls in the first bucket whose bound is >= age, else the overflow bucket. Reserve = sum over buckets of round-half-up(value*bp/10000). Return {values, reserve}.

Why this case matters

Inventory valuation and cost-of-goods decisions depend on this rule.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(x):
    bounds = x['buckets']
    vals = [0] * (len(bounds) + 1)
    for day, q, c in x['layers']:
        age = x['today'] - day
        if age < 0:
            continue
        i = 0
        while i < len(bounds) - 1 and age > bounds[i]:
            i += 1
        vals[i] += q * c
    reserve = sum((v * bp + 5000) // 10000 for v, bp in zip(vals, x['reserve_bp']))
    return {'values': vals, 'reserve': reserve}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 101], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 101, 21], 'reserve': 36}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4001]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4001, 0], 'reserve': 1200}], ['in transit', {'layers': [[106, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 26]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [52, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 51]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1050], 'reserve': 1050}], ['empty', {'layers': [], 'today': 101, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 42]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 84, 0], 'reserve': 42}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 102], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 102, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4002]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4002, 0], 'reserve': 1201}], ['in transit', {'layers': [[107, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 27]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [54, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 52]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1051], 'reserve': 1051}], ['empty', {'layers': [], 'today': 102, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 43]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 86, 0], 'reserve': 43}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 103], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 103, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4003]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4003, 0], 'reserve': 1201}], ['in transit', {'layers': [[108, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 28]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [56, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 53]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1052], 'reserve': 1052}], ['empty', {'layers': [], 'today': 103, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 44]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 88, 0], 'reserve': 44}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 104], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 104, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4004]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4004, 0], 'reserve': 1201}], ['in transit', {'layers': [[109, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 29]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [58, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 54]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1053], 'reserve': 1053}], ['empty', {'layers': [], 'today': 104, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 45]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 90, 0], 'reserve': 45}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 105], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 105, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4005]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4005, 0], 'reserve': 1201}], ['in transit', {'layers': [[110, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 30]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [60, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 55]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1054], 'reserve': 1054}], ['empty', {'layers': [], 'today': 105, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 46]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 92, 0], 'reserve': 46}]]]
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
mixed ages	`{'reserve': 31, 'values': [110, 0, 122, 0]}`	`{'reserve': 36, 'values': [110, 0, 101, 21]}`	Failed
bucket edges	`{'reserve': 1200, 'values': [1000, 2000, 4001, 0]}`	`{'reserve': 1200, 'values': [1000, 2000, 4001, 0]}`	Passed
in transit	`{'reserve': 0, 'values': [10, 0, 0, 0]}`	`{'reserve': 0, 'values': [10, 0, 0, 0]}`	Passed
same day	`{'reserve': 1, 'values': [52, 0]}`	`{'reserve': 1, 'values': [52, 0]}`	Passed
very old	`{'reserve': 210, 'values': [0, 1050, 0]}`	`{'reserve': 1050, 'values': [0, 0, 1050]}`	Failed
empty	`{'reserve': 0, 'values': [0, 0, 0]}`	`{'reserve': 0, 'values': [0, 0, 0]}`	Passed
one step	`{'reserve': 42, 'values': [80, 84, 0]}`	`{'reserve': 42, 'values': [80, 84, 0]}`	Passed

SHA-256 / 7c4844af6b98284c95abfab37e790b01b7f986569ea4da21647000f22c179762

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(x):
    bounds = x['buckets']
    vals = [0] * (len(bounds) + 1)
    for day, q, c in x['layers']:
        age = x['today'] - day
        if age < 0:
            continue
        i = 0
        while (i < len(bounds) - 1 or age > 365 and i < len(bounds)) and age > bounds[i]:
            i += 1
        vals[i] += q * c
    reserve = sum((v * bp + 5000) // 10000 for v, bp in zip(vals, x['reserve_bp']))
    return {'values': vals, 'reserve': reserve}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 101], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 101, 21], 'reserve': 36}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4001]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4001, 0], 'reserve': 1200}], ['in transit', {'layers': [[106, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 26]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [52, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 51]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1050], 'reserve': 1050}], ['empty', {'layers': [], 'today': 101, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 42]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 84, 0], 'reserve': 42}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 102], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 102, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4002]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4002, 0], 'reserve': 1201}], ['in transit', {'layers': [[107, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 27]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [54, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 52]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1051], 'reserve': 1051}], ['empty', {'layers': [], 'today': 102, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 43]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 86, 0], 'reserve': 43}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 103], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 103, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4003]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4003, 0], 'reserve': 1201}], ['in transit', {'layers': [[108, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 28]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [56, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 53]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1052], 'reserve': 1052}], ['empty', {'layers': [], 'today': 103, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 44]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 88, 0], 'reserve': 44}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 104], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 104, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4004]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4004, 0], 'reserve': 1201}], ['in transit', {'layers': [[109, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 29]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [58, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 54]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1053], 'reserve': 1053}], ['empty', {'layers': [], 'today': 104, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 45]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 90, 0], 'reserve': 45}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 105], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 105, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4005]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4005, 0], 'reserve': 1201}], ['in transit', {'layers': [[110, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 30]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [60, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 55]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1054], 'reserve': 1054}], ['empty', {'layers': [], 'today': 105, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 46]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 92, 0], 'reserve': 46}]]]
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
mixed ages	`{'reserve': 31, 'values': [110, 0, 122, 0]}`	`{'reserve': 36, 'values': [110, 0, 101, 21]}`	Failed
bucket edges	`{'reserve': 1200, 'values': [1000, 2000, 4001, 0]}`	`{'reserve': 1200, 'values': [1000, 2000, 4001, 0]}`	Passed
in transit	`{'reserve': 0, 'values': [10, 0, 0, 0]}`	`{'reserve': 0, 'values': [10, 0, 0, 0]}`	Passed
same day	`{'reserve': 1, 'values': [52, 0]}`	`{'reserve': 1, 'values': [52, 0]}`	Passed
very old	`{'reserve': 251, 'values': [0, 999, 51]}`	`{'reserve': 1050, 'values': [0, 0, 1050]}`	Failed
empty	`{'reserve': 0, 'values': [0, 0, 0]}`	`{'reserve': 0, 'values': [0, 0, 0]}`	Passed
one step	`{'reserve': 42, 'values': [80, 84, 0]}`	`{'reserve': 42, 'values': [80, 84, 0]}`	Passed

SHA-256 / ab9f5f3864d7ded5a30196200a5c2c4a6bdc33e9316a489bb14c6826626ddeb4

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(x):
    bounds = x['buckets']
    vals = [0] * (len(bounds) + 1)
    for day, q, c in x['layers']:
        age = x['today'] - day
        if age < 0:
            continue
        i = 0
        while i < len(bounds) and age > bounds[i]:
            i += 1
        vals[i] += q * c
    reserve = sum((v * bp + 5000) // 10000 for v, bp in zip(vals, x['reserve_bp']))
    return {'values': vals, 'reserve': reserve}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 101], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 101, 21], 'reserve': 36}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4001]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4001, 0], 'reserve': 1200}], ['in transit', {'layers': [[106, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 26]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [52, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 51]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1050], 'reserve': 1050}], ['empty', {'layers': [], 'today': 101, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 42]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 84, 0], 'reserve': 42}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 102], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 102, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4002]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4002, 0], 'reserve': 1201}], ['in transit', {'layers': [[107, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 27]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [54, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 52]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1051], 'reserve': 1051}], ['empty', {'layers': [], 'today': 102, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 43]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 86, 0], 'reserve': 43}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 103], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 103, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4003]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4003, 0], 'reserve': 1201}], ['in transit', {'layers': [[108, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 28]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [56, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 53]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1052], 'reserve': 1052}], ['empty', {'layers': [], 'today': 103, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 44]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 88, 0], 'reserve': 44}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 104], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 104, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4004]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4004, 0], 'reserve': 1201}], ['in transit', {'layers': [[109, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 29]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [58, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 54]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1053], 'reserve': 1053}], ['empty', {'layers': [], 'today': 104, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 45]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 90, 0], 'reserve': 45}]], [['mixed ages', {'layers': [[100, 5, 10], [70, 2, 30], [30, 1, 105], [5, 3, 7]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [110, 0, 105, 21], 'reserve': 37}], ['bucket edges', {'layers': [[70, 1, 1000], [40, 1, 2000], [10, 1, 4005]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [1000, 2000, 4005, 0], 'reserve': 1201}], ['in transit', {'layers': [[110, 4, 50], [90, 1, 10]], 'today': 100, 'buckets': [30, 60, 90], 'reserve_bp': [0, 1000, 2500, 5000]}, {'values': [10, 0, 0, 0], 'reserve': 0}], ['same day', {'layers': [[100, 2, 30]], 'today': 100, 'buckets': [30], 'reserve_bp': [100, 9000]}, {'values': [60, 0], 'reserve': 1}], ['very old', {'layers': [[1, 3, 333], [-200, 1, 55]], 'today': 300, 'buckets': [60, 120], 'reserve_bp': [0, 2000, 10000]}, {'values': [0, 0, 1054], 'reserve': 1054}], ['empty', {'layers': [], 'today': 105, 'buckets': [30, 60], 'reserve_bp': [0, 1000, 3000]}, {'values': [0, 0, 0], 'reserve': 0}], ['one step', {'layers': [[69, 2, 40], [68, 2, 46]], 'today': 100, 'buckets': [31, 32], 'reserve_bp': [0, 5000, 10000]}, {'values': [80, 92, 0], 'reserve': 46}]]]
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
mixed ages	`{'reserve': 36, 'values': [110, 0, 101, 21]}`	`{'reserve': 36, 'values': [110, 0, 101, 21]}`	Passed
bucket edges	`{'reserve': 1200, 'values': [1000, 2000, 4001, 0]}`	`{'reserve': 1200, 'values': [1000, 2000, 4001, 0]}`	Passed
in transit	`{'reserve': 0, 'values': [10, 0, 0, 0]}`	`{'reserve': 0, 'values': [10, 0, 0, 0]}`	Passed
same day	`{'reserve': 1, 'values': [52, 0]}`	`{'reserve': 1, 'values': [52, 0]}`	Passed
very old	`{'reserve': 1050, 'values': [0, 0, 1050]}`	`{'reserve': 1050, 'values': [0, 0, 1050]}`	Passed
empty	`{'reserve': 0, 'values': [0, 0, 0]}`	`{'reserve': 0, 'values': [0, 0, 0]}`	Passed
one step	`{'reserve': 42, 'values': [80, 84, 0]}`	`{'reserve': 42, 'values': [80, 84, 0]}`	Passed

SHA-256 / 1f0c153919e310af93c42db05dd85f718a76a7e90357a5ae935e81ed55d9612a

Verification & scope

Stipulated bounded teaching model with explicit toy rules; not an accounting-standard 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 2026-09-29T14:46:43.850603+00:00.

Case digest / 29a7c0d190106f79029d12bf41c5a1c7a7d08df401defbcadddfb4bdc1893113