FAILURE MAP
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FA-58271 / Double-entry ledger accounting / Open access

Receivables subledger tie-out: open customer count · case 01

Customers with credit balances are not counted as open.

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

ROOT CAUSE

Only positive balances count as open accounts.

VERIFIED REPAIR

Count every customer with a nonzero balance.

Unsuccessful approach: Counting every customer includes fully settled accounts.

Case contract

x = {'control': [[day, amount]], 'sub': {customer: [[day, amount]]}, 'as_of': day}. Only rows dated on or before as_of count. The subledger total nets every customer balance, including credit (negative) balances. Return {'control', 'subledger', 'difference': control - subledger, 'credit_balances': customers with negative balance sorted by name, 'open_customers': count of nonzero balances}.

Why this case matters

Ledger software must keep debits equal to credits and apply normal-balance, period and cutoff rules exactly; small sign or boundary slips silently misstate financial statements.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    cut = x['as_of']
    control = sum(a for d, a in x['control'] if d <= cut)
    per = {}
    for cust, rows in x['sub'].items():
        per[cust] = sum(a for d, a in rows if d <= cut)
    sub_total = sum(per.values())
    credit = sorted(c for c, v in per.items() if v < 0)
    return {'control': control, 'subledger': sub_total, 'difference': control - sub_total, 'credit_balances': credit, 'open_customers': sum(1 for v in per.values() if v > 0)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: open customer count', {'control': [[9, 250], [10, 100], [11, 400]], 'sub': {'dyna': [[1, 400], [11, 400]], 'acme': [[1, -300], [10, 250], [1, -80]], 'bolt': [[1, -80]]}, 'as_of': 10}, {'control': 350, 'subledger': 190, 'difference': 160, 'credit_balances': ['acme', 'bolt'], 'open_customers': 3}], ['regression: open customer count, partial-repair probe', {'control': [[5, 100], [19, -80], [21, -80]], 'sub': {'bolt': [[5, -80], [1, 250], [5, -80]], 'acme': [[21, 100]], 'dyna': [[20, 400], [1, 250], [20, 100]], 'crux': [[20, 400], [5, 100]]}, 'as_of': 20}, {'control': 20, 'subledger': 1340, 'difference': -1320, 'credit_balances': [], 'open_customers': 3}], ['control 1', {'control': [[21, 400], [5, 250], [19, 250], [20, 400], [19, -80]], 'sub': {'bolt': [[5, 250]]}, 'as_of': 20}, {'control': 820, 'subledger': 250, 'difference': 570, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, 100], [10, 100], [9, 400], [10, 100], [1, 250], [9, 250]], 'sub': {'dyna': [[1, 400], [11, 400], [1, 400]]}, 'as_of': 10}, {'control': 1200, 'subledger': 800, 'difference': 400, 'credit_balances': [], 'open_customers': 1}], ['control 3', {'control': [[10, 400], [10, 100], [9, 250], [11, 250], [1, 400]], 'sub': {'bolt': [[11, 400], [10, 400], [5, 100]]}, 'as_of': 10}, {'control': 1150, 'subledger': 500, 'difference': 650, 'credit_balances': [], 'open_customers': 1}], ['control 4', {'control': [[5, 400], [1, 250], [9, -80], [5, -80], [5, 250]], 'sub': {'acme': [[5, 250], [11, 100]], 'crux': [[5, 400]], 'dyna': [[5, 250]]}, 'as_of': 10}, {'control': 740, 'subledger': 900, 'difference': -160, 'credit_balances': [], 'open_customers': 3}], ['control 5', {'control': [[11, 250], [1, -80], [11, 400], [1, -80]], 'sub': {'acme': [[1, 250], [1, -80], [11, 250]], 'bolt': [[11, 100]], 'dyna': [[11, -80]]}, 'as_of': 10}, {'control': -160, 'subledger': 170, 'difference': -330, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[31, 400], [30, 250]], 'sub': {'bolt': [[1, 400], [1, 400], [5, -300]], 'acme': [[32, 250]], 'crux': [[5, -300], [31, 400], [5, -300]]}, 'as_of': 31}, {'control': 650, 'subledger': 300, 'difference': 350, 'credit_balances': ['crux'], 'open_customers': 2}], ['control 1', {'control': [[1, 400], [11, 250]], 'sub': {'dyna': [[1, 250]], 'crux': [[1, 250], [1, 250], [1, 100]], 'acme': [[10, 250], [1, 250], [11, 250]], 'bolt': [[11, 250], [5, 400]]}, 'as_of': 10}, {'control': 400, 'subledger': 1750, 'difference': -1350, 'credit_balances': [], 'open_customers': 4}], ['control 2', {'control': [[20, 250], [19, 100], [5, 400]], 'sub': {'bolt': [[20, 250]], 'acme': [[1, -300], [1, 100], [1, 250]]}, 'as_of': 20}, {'control': 750, 'subledger': 300, 'difference': 450, 'credit_balances': [], 'open_customers': 2}], ['control 3', {'control': [[5, 400], [20, -80], [19, 250]], 'sub': {'acme': [[21, 250]], 'bolt': [[20, 250], [1, -80], [1, -80]], 'dyna': [[21, -80], [20, 100]], 'crux': [[5, 400], [21, 400], [20, -300]]}, 'as_of': 20}, {'control': 570, 'subledger': 290, 'difference': 280, 'credit_balances': [], 'open_customers': 3}], ['control 4', {'control': [[10, 250], [9, -80], [1, 250], [1, 100]], 'sub': {'dyna': [[1, 400], [10, 400]], 'acme': [[10, 250], [5, 400], [11, -300]], 'crux': [[11, 250], [1, 400], [5, -300]], 'bolt': [[5, 250]]}, 'as_of': 10}, {'control': 520, 'subledger': 1800, 'difference': -1280, 'credit_balances': [], 'open_customers': 4}], ['control 5', {'control': [[5, -80], [19, 400], [1, -80]], 'sub': {'crux': [[21, -300], [21, 400]], 'bolt': [[1, 250], [21, 250]], 'dyna': [[21, -300], [20, 250], [5, 250]]}, 'as_of': 20}, {'control': 240, 'subledger': 750, 'difference': -510, 'credit_balances': [], 'open_customers': 2}], ['control 6', {'control': [[10, 100], [5, 250], [5, 400], [11, -80], [1, 400], [9, 400]], 'sub': {'dyna': [[5, 250]]}, 'as_of': 10}, {'control': 1550, 'subledger': 250, 'difference': 1300, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[9, 250], [11, 100], [11, -80], [11, 250]], 'sub': {'dyna': [[1, 250], [11, 400], [10, -80]], 'acme': [[11, -300], [1, 400], [1, 400]], 'bolt': [[1, -300]]}, 'as_of': 10}, {'control': 250, 'subledger': 670, 'difference': -420, 'credit_balances': ['bolt'], 'open_customers': 3}], ['regression: open customer count, partial-repair probe', {'control': [[5, 400], [1, 250], [5, -80], [5, 250], [11, -80], [1, 400]], 'sub': {'dyna': [[11, 100]], 'acme': [[5, 400], [1, 100]], 'crux': [[5, 400], [5, -300]]}, 'as_of': 10}, {'control': 1220, 'subledger': 600, 'difference': 620, 'credit_balances': [], 'open_customers': 2}], ['control 1', {'control': [[1, -80], [1, 100], [32, 400], [31, 250]], 'sub': {'bolt': [[1, 250]]}, 'as_of': 31}, {'control': 270, 'subledger': 250, 'difference': 20, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, 250], [1, 400], [11, 100]], 'sub': {'crux': [[5, -80], [1, 250], [1, 250]]}, 'as_of': 10}, {'control': 650, 'subledger': 420, 'difference': 230, 'credit_balances': [], 'open_customers': 1}], ['control 3', {'control': [[5, 250], [30, 400], [30, -80], [1, -80], [5, 250]], 'sub': {'bolt': [[5, 250]], 'acme': [[1, 250]], 'dyna': [[31, 400]]}, 'as_of': 31}, {'control': 740, 'subledger': 900, 'difference': -160, 'credit_balances': [], 'open_customers': 3}], ['control 4', {'control': [[19, 100], [21, 250], [20, -80], [20, -80], [19, 400], [21, 100]], 'sub': {'dyna': [[21, 100]], 'acme': [[21, 100], [21, 400], [20, 250]], 'crux': [[20, -80], [21, -80], [5, 250]]}, 'as_of': 20}, {'control': 340, 'subledger': 420, 'difference': -80, 'credit_balances': [], 'open_customers': 2}], ['control 5', {'control': [[31, -80], [32, 400], [31, -80], [5, -80], [31, 250]], 'sub': {'dyna': [[1, 400], [1, 250]], 'acme': [[32, -80], [31, 100]]}, 'as_of': 31}, {'control': 10, 'subledger': 750, 'difference': -740, 'credit_balances': [], 'open_customers': 2}]], [['regression: open customer count', {'control': [[31, -80], [5, 100], [31, 100]], 'sub': {'crux': [[32, 250]], 'dyna': [[32, 250]], 'acme': [[1, -300], [32, 250]]}, 'as_of': 31}, {'control': 120, 'subledger': -300, 'difference': 420, 'credit_balances': ['acme'], 'open_customers': 1}], ['control 1', {'control': [[20, -80], [21, 100]], 'sub': {'dyna': [[1, -80], [20, 250]], 'bolt': [[1, -300], [20, 400], [21, -300]]}, 'as_of': 20}, {'control': -80, 'subledger': 270, 'difference': -350, 'credit_balances': [], 'open_customers': 2}], ['control 2', {'control': [[1, -80], [20, -80], [19, -80], [19, -80], [21, 400]], 'sub': {'acme': [[21, 250]]}, 'as_of': 20}, {'control': -320, 'subledger': 0, 'difference': -320, 'credit_balances': [], 'open_customers': 0}], ['control 3', {'control': [[5, 250], [5, 400], [1, -80], [31, 100], [30, 100]], 'sub': {'dyna': [[32, -300]], 'crux': [[5, 250], [1, 250]], 'acme': [[31, 400]]}, 'as_of': 31}, {'control': 770, 'subledger': 900, 'difference': -130, 'credit_balances': [], 'open_customers': 2}], ['control 4', {'control': [[31, 250], [1, -80], [5, 100], [31, 250], [5, 100]], 'sub': {'crux': [[32, -300], [1, 250]]}, 'as_of': 31}, {'control': 620, 'subledger': 250, 'difference': 370, 'credit_balances': [], 'open_customers': 1}], ['control 5', {'control': [[31, 250], [5, -80], [1, 400], [32, 400], [1, 400]], 'sub': {'crux': [[5, 250], [1, 400]]}, 'as_of': 31}, {'control': 970, 'subledger': 650, 'difference': 320, 'credit_balances': [], 'open_customers': 1}], ['control 6', {'control': [[1, 100], [11, 100], [1, 100], [9, 400], [9, 100], [9, 100]], 'sub': {'dyna': [[1, 100], [5, 100]]}, 'as_of': 10}, {'control': 800, 'subledger': 200, 'difference': 600, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[5, 100], [5, 250], [19, -80], [21, 250], [21, 250]], 'sub': {'crux': [[20, -80], [20, -80]], 'acme': [[21, 100]]}, 'as_of': 20}, {'control': 270, 'subledger': -160, 'difference': 430, 'credit_balances': ['crux'], 'open_customers': 1}], ['control 1', {'control': [[1, -80], [5, 100], [20, 400], [19, 250], [1, 250]], 'sub': {'crux': [[20, 250], [20, -80], [20, 250]]}, 'as_of': 20}, {'control': 920, 'subledger': 420, 'difference': 500, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, -80], [11, 400]], 'sub': {'bolt': [[5, 100], [5, 250]], 'acme': [[11, 100], [11, -80], [10, 250]]}, 'as_of': 10}, {'control': -80, 'subledger': 600, 'difference': -680, 'credit_balances': [], 'open_customers': 2}], ['control 3', {'control': [[1, 100], [1, 250], [5, 250], [1, 100], [1, 400], [5, -80]], 'sub': {'bolt': [[10, -80], [10, 400]], 'crux': [[1, 250], [10, 250]]}, 'as_of': 10}, {'control': 1020, 'subledger': 820, 'difference': 200, 'credit_balances': [], 'open_customers': 2}], ['control 4', {'control': [[32, 250], [1, 100], [32, 100], [31, 100], [1, -80]], 'sub': {'dyna': [[5, 100]], 'acme': [[5, 400], [5, -80]], 'crux': [[32, -80]], 'bolt': [[32, -80]]}, 'as_of': 31}, {'control': 120, 'subledger': 420, 'difference': -300, 'credit_balances': [], 'open_customers': 2}], ['control 5', {'control': [[5, 400], [11, 100]], 'sub': {'bolt': [[5, 400], [1, -80]], 'acme': [[5, 400], [1, 100], [5, -300]], 'dyna': [[1, 100]]}, 'as_of': 10}, {'control': 400, 'subledger': 620, 'difference': -220, 'credit_balances': [], 'open_customers': 3}], ['control 6', {'control': [[31, 400], [32, 400]], 'sub': {'acme': [[1, -80], [31, 400]]}, 'as_of': 31}, {'control': 400, 'subledger': 320, 'difference': 80, 'credit_balances': [], 'open_customers': 1}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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: open customer count{'control': 350, 'credit_balances': ['acme', 'bolt'], 'difference': 160, 'open_customers': 1, 'subledger': 190}{'control': 350, 'credit_balances': ['acme', 'bolt'], 'difference': 160, 'open_customers': 3, 'subledger': 190}Failed
regression: open customer count, partial-repair probe{'control': 20, 'credit_balances': [], 'difference': -1320, 'open_customers': 3, 'subledger': 1340}{'control': 20, 'credit_balances': [], 'difference': -1320, 'open_customers': 3, 'subledger': 1340}Passed
control 1{'control': 820, 'credit_balances': [], 'difference': 570, 'open_customers': 1, 'subledger': 250}{'control': 820, 'credit_balances': [], 'difference': 570, 'open_customers': 1, 'subledger': 250}Passed
control 2{'control': 1200, 'credit_balances': [], 'difference': 400, 'open_customers': 1, 'subledger': 800}{'control': 1200, 'credit_balances': [], 'difference': 400, 'open_customers': 1, 'subledger': 800}Passed
control 3{'control': 1150, 'credit_balances': [], 'difference': 650, 'open_customers': 1, 'subledger': 500}{'control': 1150, 'credit_balances': [], 'difference': 650, 'open_customers': 1, 'subledger': 500}Passed
control 4{'control': 740, 'credit_balances': [], 'difference': -160, 'open_customers': 3, 'subledger': 900}{'control': 740, 'credit_balances': [], 'difference': -160, 'open_customers': 3, 'subledger': 900}Passed
control 5{'control': -160, 'credit_balances': [], 'difference': -330, 'open_customers': 1, 'subledger': 170}{'control': -160, 'credit_balances': [], 'difference': -330, 'open_customers': 1, 'subledger': 170}Passed

SHA-256 / ff21f3b05d3024413cda9e60fe85e992ac61a5dc70985e5f7ad84ed01c580b3e

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    cut = x['as_of']
    control = sum(a for d, a in x['control'] if d <= cut)
    per = {}
    for cust, rows in x['sub'].items():
        per[cust] = sum(a for d, a in rows if d <= cut)
    sub_total = sum(per.values())
    credit = sorted(c for c, v in per.items() if v < 0)
    return {'control': control, 'subledger': sub_total, 'difference': control - sub_total, 'credit_balances': credit, 'open_customers': len(per)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: open customer count', {'control': [[9, 250], [10, 100], [11, 400]], 'sub': {'dyna': [[1, 400], [11, 400]], 'acme': [[1, -300], [10, 250], [1, -80]], 'bolt': [[1, -80]]}, 'as_of': 10}, {'control': 350, 'subledger': 190, 'difference': 160, 'credit_balances': ['acme', 'bolt'], 'open_customers': 3}], ['regression: open customer count, partial-repair probe', {'control': [[5, 100], [19, -80], [21, -80]], 'sub': {'bolt': [[5, -80], [1, 250], [5, -80]], 'acme': [[21, 100]], 'dyna': [[20, 400], [1, 250], [20, 100]], 'crux': [[20, 400], [5, 100]]}, 'as_of': 20}, {'control': 20, 'subledger': 1340, 'difference': -1320, 'credit_balances': [], 'open_customers': 3}], ['control 1', {'control': [[21, 400], [5, 250], [19, 250], [20, 400], [19, -80]], 'sub': {'bolt': [[5, 250]]}, 'as_of': 20}, {'control': 820, 'subledger': 250, 'difference': 570, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, 100], [10, 100], [9, 400], [10, 100], [1, 250], [9, 250]], 'sub': {'dyna': [[1, 400], [11, 400], [1, 400]]}, 'as_of': 10}, {'control': 1200, 'subledger': 800, 'difference': 400, 'credit_balances': [], 'open_customers': 1}], ['control 3', {'control': [[10, 400], [10, 100], [9, 250], [11, 250], [1, 400]], 'sub': {'bolt': [[11, 400], [10, 400], [5, 100]]}, 'as_of': 10}, {'control': 1150, 'subledger': 500, 'difference': 650, 'credit_balances': [], 'open_customers': 1}], ['control 4', {'control': [[5, 400], [1, 250], [9, -80], [5, -80], [5, 250]], 'sub': {'acme': [[5, 250], [11, 100]], 'crux': [[5, 400]], 'dyna': [[5, 250]]}, 'as_of': 10}, {'control': 740, 'subledger': 900, 'difference': -160, 'credit_balances': [], 'open_customers': 3}], ['control 5', {'control': [[11, 250], [1, -80], [11, 400], [1, -80]], 'sub': {'acme': [[1, 250], [1, -80], [11, 250]], 'bolt': [[11, 100]], 'dyna': [[11, -80]]}, 'as_of': 10}, {'control': -160, 'subledger': 170, 'difference': -330, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[31, 400], [30, 250]], 'sub': {'bolt': [[1, 400], [1, 400], [5, -300]], 'acme': [[32, 250]], 'crux': [[5, -300], [31, 400], [5, -300]]}, 'as_of': 31}, {'control': 650, 'subledger': 300, 'difference': 350, 'credit_balances': ['crux'], 'open_customers': 2}], ['control 1', {'control': [[1, 400], [11, 250]], 'sub': {'dyna': [[1, 250]], 'crux': [[1, 250], [1, 250], [1, 100]], 'acme': [[10, 250], [1, 250], [11, 250]], 'bolt': [[11, 250], [5, 400]]}, 'as_of': 10}, {'control': 400, 'subledger': 1750, 'difference': -1350, 'credit_balances': [], 'open_customers': 4}], ['control 2', {'control': [[20, 250], [19, 100], [5, 400]], 'sub': {'bolt': [[20, 250]], 'acme': [[1, -300], [1, 100], [1, 250]]}, 'as_of': 20}, {'control': 750, 'subledger': 300, 'difference': 450, 'credit_balances': [], 'open_customers': 2}], ['control 3', {'control': [[5, 400], [20, -80], [19, 250]], 'sub': {'acme': [[21, 250]], 'bolt': [[20, 250], [1, -80], [1, -80]], 'dyna': [[21, -80], [20, 100]], 'crux': [[5, 400], [21, 400], [20, -300]]}, 'as_of': 20}, {'control': 570, 'subledger': 290, 'difference': 280, 'credit_balances': [], 'open_customers': 3}], ['control 4', {'control': [[10, 250], [9, -80], [1, 250], [1, 100]], 'sub': {'dyna': [[1, 400], [10, 400]], 'acme': [[10, 250], [5, 400], [11, -300]], 'crux': [[11, 250], [1, 400], [5, -300]], 'bolt': [[5, 250]]}, 'as_of': 10}, {'control': 520, 'subledger': 1800, 'difference': -1280, 'credit_balances': [], 'open_customers': 4}], ['control 5', {'control': [[5, -80], [19, 400], [1, -80]], 'sub': {'crux': [[21, -300], [21, 400]], 'bolt': [[1, 250], [21, 250]], 'dyna': [[21, -300], [20, 250], [5, 250]]}, 'as_of': 20}, {'control': 240, 'subledger': 750, 'difference': -510, 'credit_balances': [], 'open_customers': 2}], ['control 6', {'control': [[10, 100], [5, 250], [5, 400], [11, -80], [1, 400], [9, 400]], 'sub': {'dyna': [[5, 250]]}, 'as_of': 10}, {'control': 1550, 'subledger': 250, 'difference': 1300, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[9, 250], [11, 100], [11, -80], [11, 250]], 'sub': {'dyna': [[1, 250], [11, 400], [10, -80]], 'acme': [[11, -300], [1, 400], [1, 400]], 'bolt': [[1, -300]]}, 'as_of': 10}, {'control': 250, 'subledger': 670, 'difference': -420, 'credit_balances': ['bolt'], 'open_customers': 3}], ['regression: open customer count, partial-repair probe', {'control': [[5, 400], [1, 250], [5, -80], [5, 250], [11, -80], [1, 400]], 'sub': {'dyna': [[11, 100]], 'acme': [[5, 400], [1, 100]], 'crux': [[5, 400], [5, -300]]}, 'as_of': 10}, {'control': 1220, 'subledger': 600, 'difference': 620, 'credit_balances': [], 'open_customers': 2}], ['control 1', {'control': [[1, -80], [1, 100], [32, 400], [31, 250]], 'sub': {'bolt': [[1, 250]]}, 'as_of': 31}, {'control': 270, 'subledger': 250, 'difference': 20, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, 250], [1, 400], [11, 100]], 'sub': {'crux': [[5, -80], [1, 250], [1, 250]]}, 'as_of': 10}, {'control': 650, 'subledger': 420, 'difference': 230, 'credit_balances': [], 'open_customers': 1}], ['control 3', {'control': [[5, 250], [30, 400], [30, -80], [1, -80], [5, 250]], 'sub': {'bolt': [[5, 250]], 'acme': [[1, 250]], 'dyna': [[31, 400]]}, 'as_of': 31}, {'control': 740, 'subledger': 900, 'difference': -160, 'credit_balances': [], 'open_customers': 3}], ['control 4', {'control': [[19, 100], [21, 250], [20, -80], [20, -80], [19, 400], [21, 100]], 'sub': {'dyna': [[21, 100]], 'acme': [[21, 100], [21, 400], [20, 250]], 'crux': [[20, -80], [21, -80], [5, 250]]}, 'as_of': 20}, {'control': 340, 'subledger': 420, 'difference': -80, 'credit_balances': [], 'open_customers': 2}], ['control 5', {'control': [[31, -80], [32, 400], [31, -80], [5, -80], [31, 250]], 'sub': {'dyna': [[1, 400], [1, 250]], 'acme': [[32, -80], [31, 100]]}, 'as_of': 31}, {'control': 10, 'subledger': 750, 'difference': -740, 'credit_balances': [], 'open_customers': 2}]], [['regression: open customer count', {'control': [[31, -80], [5, 100], [31, 100]], 'sub': {'crux': [[32, 250]], 'dyna': [[32, 250]], 'acme': [[1, -300], [32, 250]]}, 'as_of': 31}, {'control': 120, 'subledger': -300, 'difference': 420, 'credit_balances': ['acme'], 'open_customers': 1}], ['control 1', {'control': [[20, -80], [21, 100]], 'sub': {'dyna': [[1, -80], [20, 250]], 'bolt': [[1, -300], [20, 400], [21, -300]]}, 'as_of': 20}, {'control': -80, 'subledger': 270, 'difference': -350, 'credit_balances': [], 'open_customers': 2}], ['control 2', {'control': [[1, -80], [20, -80], [19, -80], [19, -80], [21, 400]], 'sub': {'acme': [[21, 250]]}, 'as_of': 20}, {'control': -320, 'subledger': 0, 'difference': -320, 'credit_balances': [], 'open_customers': 0}], ['control 3', {'control': [[5, 250], [5, 400], [1, -80], [31, 100], [30, 100]], 'sub': {'dyna': [[32, -300]], 'crux': [[5, 250], [1, 250]], 'acme': [[31, 400]]}, 'as_of': 31}, {'control': 770, 'subledger': 900, 'difference': -130, 'credit_balances': [], 'open_customers': 2}], ['control 4', {'control': [[31, 250], [1, -80], [5, 100], [31, 250], [5, 100]], 'sub': {'crux': [[32, -300], [1, 250]]}, 'as_of': 31}, {'control': 620, 'subledger': 250, 'difference': 370, 'credit_balances': [], 'open_customers': 1}], ['control 5', {'control': [[31, 250], [5, -80], [1, 400], [32, 400], [1, 400]], 'sub': {'crux': [[5, 250], [1, 400]]}, 'as_of': 31}, {'control': 970, 'subledger': 650, 'difference': 320, 'credit_balances': [], 'open_customers': 1}], ['control 6', {'control': [[1, 100], [11, 100], [1, 100], [9, 400], [9, 100], [9, 100]], 'sub': {'dyna': [[1, 100], [5, 100]]}, 'as_of': 10}, {'control': 800, 'subledger': 200, 'difference': 600, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[5, 100], [5, 250], [19, -80], [21, 250], [21, 250]], 'sub': {'crux': [[20, -80], [20, -80]], 'acme': [[21, 100]]}, 'as_of': 20}, {'control': 270, 'subledger': -160, 'difference': 430, 'credit_balances': ['crux'], 'open_customers': 1}], ['control 1', {'control': [[1, -80], [5, 100], [20, 400], [19, 250], [1, 250]], 'sub': {'crux': [[20, 250], [20, -80], [20, 250]]}, 'as_of': 20}, {'control': 920, 'subledger': 420, 'difference': 500, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, -80], [11, 400]], 'sub': {'bolt': [[5, 100], [5, 250]], 'acme': [[11, 100], [11, -80], [10, 250]]}, 'as_of': 10}, {'control': -80, 'subledger': 600, 'difference': -680, 'credit_balances': [], 'open_customers': 2}], ['control 3', {'control': [[1, 100], [1, 250], [5, 250], [1, 100], [1, 400], [5, -80]], 'sub': {'bolt': [[10, -80], [10, 400]], 'crux': [[1, 250], [10, 250]]}, 'as_of': 10}, {'control': 1020, 'subledger': 820, 'difference': 200, 'credit_balances': [], 'open_customers': 2}], ['control 4', {'control': [[32, 250], [1, 100], [32, 100], [31, 100], [1, -80]], 'sub': {'dyna': [[5, 100]], 'acme': [[5, 400], [5, -80]], 'crux': [[32, -80]], 'bolt': [[32, -80]]}, 'as_of': 31}, {'control': 120, 'subledger': 420, 'difference': -300, 'credit_balances': [], 'open_customers': 2}], ['control 5', {'control': [[5, 400], [11, 100]], 'sub': {'bolt': [[5, 400], [1, -80]], 'acme': [[5, 400], [1, 100], [5, -300]], 'dyna': [[1, 100]]}, 'as_of': 10}, {'control': 400, 'subledger': 620, 'difference': -220, 'credit_balances': [], 'open_customers': 3}], ['control 6', {'control': [[31, 400], [32, 400]], 'sub': {'acme': [[1, -80], [31, 400]]}, 'as_of': 31}, {'control': 400, 'subledger': 320, 'difference': 80, 'credit_balances': [], 'open_customers': 1}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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: open customer count{'control': 350, 'credit_balances': ['acme', 'bolt'], 'difference': 160, 'open_customers': 3, 'subledger': 190}{'control': 350, 'credit_balances': ['acme', 'bolt'], 'difference': 160, 'open_customers': 3, 'subledger': 190}Passed
regression: open customer count, partial-repair probe{'control': 20, 'credit_balances': [], 'difference': -1320, 'open_customers': 4, 'subledger': 1340}{'control': 20, 'credit_balances': [], 'difference': -1320, 'open_customers': 3, 'subledger': 1340}Failed
control 1{'control': 820, 'credit_balances': [], 'difference': 570, 'open_customers': 1, 'subledger': 250}{'control': 820, 'credit_balances': [], 'difference': 570, 'open_customers': 1, 'subledger': 250}Passed
control 2{'control': 1200, 'credit_balances': [], 'difference': 400, 'open_customers': 1, 'subledger': 800}{'control': 1200, 'credit_balances': [], 'difference': 400, 'open_customers': 1, 'subledger': 800}Passed
control 3{'control': 1150, 'credit_balances': [], 'difference': 650, 'open_customers': 1, 'subledger': 500}{'control': 1150, 'credit_balances': [], 'difference': 650, 'open_customers': 1, 'subledger': 500}Passed
control 4{'control': 740, 'credit_balances': [], 'difference': -160, 'open_customers': 3, 'subledger': 900}{'control': 740, 'credit_balances': [], 'difference': -160, 'open_customers': 3, 'subledger': 900}Passed
control 5{'control': -160, 'credit_balances': [], 'difference': -330, 'open_customers': 3, 'subledger': 170}{'control': -160, 'credit_balances': [], 'difference': -330, 'open_customers': 1, 'subledger': 170}Failed

SHA-256 / 91bfae0189adb7dcfe102a61c457e4100e7e012c8717dc17da00fc7136a8da81

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    cut = x['as_of']
    control = sum(a for d, a in x['control'] if d <= cut)
    per = {}
    for cust, rows in x['sub'].items():
        per[cust] = sum(a for d, a in rows if d <= cut)
    sub_total = sum(per.values())
    credit = sorted(c for c, v in per.items() if v < 0)
    return {'control': control, 'subledger': sub_total, 'difference': control - sub_total, 'credit_balances': credit, 'open_customers': sum(1 for v in per.values() if v != 0)}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: open customer count', {'control': [[9, 250], [10, 100], [11, 400]], 'sub': {'dyna': [[1, 400], [11, 400]], 'acme': [[1, -300], [10, 250], [1, -80]], 'bolt': [[1, -80]]}, 'as_of': 10}, {'control': 350, 'subledger': 190, 'difference': 160, 'credit_balances': ['acme', 'bolt'], 'open_customers': 3}], ['regression: open customer count, partial-repair probe', {'control': [[5, 100], [19, -80], [21, -80]], 'sub': {'bolt': [[5, -80], [1, 250], [5, -80]], 'acme': [[21, 100]], 'dyna': [[20, 400], [1, 250], [20, 100]], 'crux': [[20, 400], [5, 100]]}, 'as_of': 20}, {'control': 20, 'subledger': 1340, 'difference': -1320, 'credit_balances': [], 'open_customers': 3}], ['control 1', {'control': [[21, 400], [5, 250], [19, 250], [20, 400], [19, -80]], 'sub': {'bolt': [[5, 250]]}, 'as_of': 20}, {'control': 820, 'subledger': 250, 'difference': 570, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, 100], [10, 100], [9, 400], [10, 100], [1, 250], [9, 250]], 'sub': {'dyna': [[1, 400], [11, 400], [1, 400]]}, 'as_of': 10}, {'control': 1200, 'subledger': 800, 'difference': 400, 'credit_balances': [], 'open_customers': 1}], ['control 3', {'control': [[10, 400], [10, 100], [9, 250], [11, 250], [1, 400]], 'sub': {'bolt': [[11, 400], [10, 400], [5, 100]]}, 'as_of': 10}, {'control': 1150, 'subledger': 500, 'difference': 650, 'credit_balances': [], 'open_customers': 1}], ['control 4', {'control': [[5, 400], [1, 250], [9, -80], [5, -80], [5, 250]], 'sub': {'acme': [[5, 250], [11, 100]], 'crux': [[5, 400]], 'dyna': [[5, 250]]}, 'as_of': 10}, {'control': 740, 'subledger': 900, 'difference': -160, 'credit_balances': [], 'open_customers': 3}], ['control 5', {'control': [[11, 250], [1, -80], [11, 400], [1, -80]], 'sub': {'acme': [[1, 250], [1, -80], [11, 250]], 'bolt': [[11, 100]], 'dyna': [[11, -80]]}, 'as_of': 10}, {'control': -160, 'subledger': 170, 'difference': -330, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[31, 400], [30, 250]], 'sub': {'bolt': [[1, 400], [1, 400], [5, -300]], 'acme': [[32, 250]], 'crux': [[5, -300], [31, 400], [5, -300]]}, 'as_of': 31}, {'control': 650, 'subledger': 300, 'difference': 350, 'credit_balances': ['crux'], 'open_customers': 2}], ['control 1', {'control': [[1, 400], [11, 250]], 'sub': {'dyna': [[1, 250]], 'crux': [[1, 250], [1, 250], [1, 100]], 'acme': [[10, 250], [1, 250], [11, 250]], 'bolt': [[11, 250], [5, 400]]}, 'as_of': 10}, {'control': 400, 'subledger': 1750, 'difference': -1350, 'credit_balances': [], 'open_customers': 4}], ['control 2', {'control': [[20, 250], [19, 100], [5, 400]], 'sub': {'bolt': [[20, 250]], 'acme': [[1, -300], [1, 100], [1, 250]]}, 'as_of': 20}, {'control': 750, 'subledger': 300, 'difference': 450, 'credit_balances': [], 'open_customers': 2}], ['control 3', {'control': [[5, 400], [20, -80], [19, 250]], 'sub': {'acme': [[21, 250]], 'bolt': [[20, 250], [1, -80], [1, -80]], 'dyna': [[21, -80], [20, 100]], 'crux': [[5, 400], [21, 400], [20, -300]]}, 'as_of': 20}, {'control': 570, 'subledger': 290, 'difference': 280, 'credit_balances': [], 'open_customers': 3}], ['control 4', {'control': [[10, 250], [9, -80], [1, 250], [1, 100]], 'sub': {'dyna': [[1, 400], [10, 400]], 'acme': [[10, 250], [5, 400], [11, -300]], 'crux': [[11, 250], [1, 400], [5, -300]], 'bolt': [[5, 250]]}, 'as_of': 10}, {'control': 520, 'subledger': 1800, 'difference': -1280, 'credit_balances': [], 'open_customers': 4}], ['control 5', {'control': [[5, -80], [19, 400], [1, -80]], 'sub': {'crux': [[21, -300], [21, 400]], 'bolt': [[1, 250], [21, 250]], 'dyna': [[21, -300], [20, 250], [5, 250]]}, 'as_of': 20}, {'control': 240, 'subledger': 750, 'difference': -510, 'credit_balances': [], 'open_customers': 2}], ['control 6', {'control': [[10, 100], [5, 250], [5, 400], [11, -80], [1, 400], [9, 400]], 'sub': {'dyna': [[5, 250]]}, 'as_of': 10}, {'control': 1550, 'subledger': 250, 'difference': 1300, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[9, 250], [11, 100], [11, -80], [11, 250]], 'sub': {'dyna': [[1, 250], [11, 400], [10, -80]], 'acme': [[11, -300], [1, 400], [1, 400]], 'bolt': [[1, -300]]}, 'as_of': 10}, {'control': 250, 'subledger': 670, 'difference': -420, 'credit_balances': ['bolt'], 'open_customers': 3}], ['regression: open customer count, partial-repair probe', {'control': [[5, 400], [1, 250], [5, -80], [5, 250], [11, -80], [1, 400]], 'sub': {'dyna': [[11, 100]], 'acme': [[5, 400], [1, 100]], 'crux': [[5, 400], [5, -300]]}, 'as_of': 10}, {'control': 1220, 'subledger': 600, 'difference': 620, 'credit_balances': [], 'open_customers': 2}], ['control 1', {'control': [[1, -80], [1, 100], [32, 400], [31, 250]], 'sub': {'bolt': [[1, 250]]}, 'as_of': 31}, {'control': 270, 'subledger': 250, 'difference': 20, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, 250], [1, 400], [11, 100]], 'sub': {'crux': [[5, -80], [1, 250], [1, 250]]}, 'as_of': 10}, {'control': 650, 'subledger': 420, 'difference': 230, 'credit_balances': [], 'open_customers': 1}], ['control 3', {'control': [[5, 250], [30, 400], [30, -80], [1, -80], [5, 250]], 'sub': {'bolt': [[5, 250]], 'acme': [[1, 250]], 'dyna': [[31, 400]]}, 'as_of': 31}, {'control': 740, 'subledger': 900, 'difference': -160, 'credit_balances': [], 'open_customers': 3}], ['control 4', {'control': [[19, 100], [21, 250], [20, -80], [20, -80], [19, 400], [21, 100]], 'sub': {'dyna': [[21, 100]], 'acme': [[21, 100], [21, 400], [20, 250]], 'crux': [[20, -80], [21, -80], [5, 250]]}, 'as_of': 20}, {'control': 340, 'subledger': 420, 'difference': -80, 'credit_balances': [], 'open_customers': 2}], ['control 5', {'control': [[31, -80], [32, 400], [31, -80], [5, -80], [31, 250]], 'sub': {'dyna': [[1, 400], [1, 250]], 'acme': [[32, -80], [31, 100]]}, 'as_of': 31}, {'control': 10, 'subledger': 750, 'difference': -740, 'credit_balances': [], 'open_customers': 2}]], [['regression: open customer count', {'control': [[31, -80], [5, 100], [31, 100]], 'sub': {'crux': [[32, 250]], 'dyna': [[32, 250]], 'acme': [[1, -300], [32, 250]]}, 'as_of': 31}, {'control': 120, 'subledger': -300, 'difference': 420, 'credit_balances': ['acme'], 'open_customers': 1}], ['control 1', {'control': [[20, -80], [21, 100]], 'sub': {'dyna': [[1, -80], [20, 250]], 'bolt': [[1, -300], [20, 400], [21, -300]]}, 'as_of': 20}, {'control': -80, 'subledger': 270, 'difference': -350, 'credit_balances': [], 'open_customers': 2}], ['control 2', {'control': [[1, -80], [20, -80], [19, -80], [19, -80], [21, 400]], 'sub': {'acme': [[21, 250]]}, 'as_of': 20}, {'control': -320, 'subledger': 0, 'difference': -320, 'credit_balances': [], 'open_customers': 0}], ['control 3', {'control': [[5, 250], [5, 400], [1, -80], [31, 100], [30, 100]], 'sub': {'dyna': [[32, -300]], 'crux': [[5, 250], [1, 250]], 'acme': [[31, 400]]}, 'as_of': 31}, {'control': 770, 'subledger': 900, 'difference': -130, 'credit_balances': [], 'open_customers': 2}], ['control 4', {'control': [[31, 250], [1, -80], [5, 100], [31, 250], [5, 100]], 'sub': {'crux': [[32, -300], [1, 250]]}, 'as_of': 31}, {'control': 620, 'subledger': 250, 'difference': 370, 'credit_balances': [], 'open_customers': 1}], ['control 5', {'control': [[31, 250], [5, -80], [1, 400], [32, 400], [1, 400]], 'sub': {'crux': [[5, 250], [1, 400]]}, 'as_of': 31}, {'control': 970, 'subledger': 650, 'difference': 320, 'credit_balances': [], 'open_customers': 1}], ['control 6', {'control': [[1, 100], [11, 100], [1, 100], [9, 400], [9, 100], [9, 100]], 'sub': {'dyna': [[1, 100], [5, 100]]}, 'as_of': 10}, {'control': 800, 'subledger': 200, 'difference': 600, 'credit_balances': [], 'open_customers': 1}]], [['regression: open customer count', {'control': [[5, 100], [5, 250], [19, -80], [21, 250], [21, 250]], 'sub': {'crux': [[20, -80], [20, -80]], 'acme': [[21, 100]]}, 'as_of': 20}, {'control': 270, 'subledger': -160, 'difference': 430, 'credit_balances': ['crux'], 'open_customers': 1}], ['control 1', {'control': [[1, -80], [5, 100], [20, 400], [19, 250], [1, 250]], 'sub': {'crux': [[20, 250], [20, -80], [20, 250]]}, 'as_of': 20}, {'control': 920, 'subledger': 420, 'difference': 500, 'credit_balances': [], 'open_customers': 1}], ['control 2', {'control': [[9, -80], [11, 400]], 'sub': {'bolt': [[5, 100], [5, 250]], 'acme': [[11, 100], [11, -80], [10, 250]]}, 'as_of': 10}, {'control': -80, 'subledger': 600, 'difference': -680, 'credit_balances': [], 'open_customers': 2}], ['control 3', {'control': [[1, 100], [1, 250], [5, 250], [1, 100], [1, 400], [5, -80]], 'sub': {'bolt': [[10, -80], [10, 400]], 'crux': [[1, 250], [10, 250]]}, 'as_of': 10}, {'control': 1020, 'subledger': 820, 'difference': 200, 'credit_balances': [], 'open_customers': 2}], ['control 4', {'control': [[32, 250], [1, 100], [32, 100], [31, 100], [1, -80]], 'sub': {'dyna': [[5, 100]], 'acme': [[5, 400], [5, -80]], 'crux': [[32, -80]], 'bolt': [[32, -80]]}, 'as_of': 31}, {'control': 120, 'subledger': 420, 'difference': -300, 'credit_balances': [], 'open_customers': 2}], ['control 5', {'control': [[5, 400], [11, 100]], 'sub': {'bolt': [[5, 400], [1, -80]], 'acme': [[5, 400], [1, 100], [5, -300]], 'dyna': [[1, 100]]}, 'as_of': 10}, {'control': 400, 'subledger': 620, 'difference': -220, 'credit_balances': [], 'open_customers': 3}], ['control 6', {'control': [[31, 400], [32, 400]], 'sub': {'acme': [[1, -80], [31, 400]]}, 'as_of': 31}, {'control': 400, 'subledger': 320, 'difference': 80, 'credit_balances': [], 'open_customers': 1}]]]
for label, args, expected in fixtures[N-1]:
    try:
        actual = solve(args)
    except Exception as exc:
        actual = 'raised ' + type(exc).__name__
    check(label, actual, 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: open customer count{'control': 350, 'credit_balances': ['acme', 'bolt'], 'difference': 160, 'open_customers': 3, 'subledger': 190}{'control': 350, 'credit_balances': ['acme', 'bolt'], 'difference': 160, 'open_customers': 3, 'subledger': 190}Passed
regression: open customer count, partial-repair probe{'control': 20, 'credit_balances': [], 'difference': -1320, 'open_customers': 3, 'subledger': 1340}{'control': 20, 'credit_balances': [], 'difference': -1320, 'open_customers': 3, 'subledger': 1340}Passed
control 1{'control': 820, 'credit_balances': [], 'difference': 570, 'open_customers': 1, 'subledger': 250}{'control': 820, 'credit_balances': [], 'difference': 570, 'open_customers': 1, 'subledger': 250}Passed
control 2{'control': 1200, 'credit_balances': [], 'difference': 400, 'open_customers': 1, 'subledger': 800}{'control': 1200, 'credit_balances': [], 'difference': 400, 'open_customers': 1, 'subledger': 800}Passed
control 3{'control': 1150, 'credit_balances': [], 'difference': 650, 'open_customers': 1, 'subledger': 500}{'control': 1150, 'credit_balances': [], 'difference': 650, 'open_customers': 1, 'subledger': 500}Passed
control 4{'control': 740, 'credit_balances': [], 'difference': -160, 'open_customers': 3, 'subledger': 900}{'control': 740, 'credit_balances': [], 'difference': -160, 'open_customers': 3, 'subledger': 900}Passed
control 5{'control': -160, 'credit_balances': [], 'difference': -330, 'open_customers': 1, 'subledger': 170}{'control': -160, 'credit_balances': [], 'difference': -330, 'open_customers': 1, 'subledger': 170}Passed

SHA-256 / ce5c48bb631d45b79dc8169ef7e09cce49f3a0651bab97ad918b396cf67f5daf

Verification & scope

A deterministic bounded teaching model with stipulated toy bookkeeping rules stated in the contract; amounts are integer cents; it makes no claim of conformance to any accounting standard or product. 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 2026-09-29T14:46:25.118329+00:00.

Case digest / 2d1dcb0f1bd537f67c677739707a7e541144b503201577cf27dd34fd6f5be1cb