FA-62211 / Currency rounding and FX conversion / Open access

The day reset clears the running total but keeps the previous floor · case 01

The first posting of a new day is reduced by the previous day's accumulated floor.

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

ROOT CAUSE

On a day change cum is reset but prev_floor keeps the old day's value.

VERIFIED REPAIR

Reset prev_floor to zero together with the cumulative total.

Unsuccessful approach: Carrying the fractional remainder into the new day contradicts the daily-reset contract.

Case contract

solve(items, rate): items are [day, amount] with integer source minor units (reversals negative) in posting order; rate is target minor units per source minor unit. Within a day, each posting's converted amount is floor(cumulative_exact) - floor(previous cumulative_exact), so daily converted postings sum to floor of the day's exact converted total. The carry (cumulative total and previous floor) resets whenever the day changes. Return the list of integer converted postings.

Why this case matters

Currency amounts must be rounded at the right stage and in the right unit, or ledgers, quotes and settlements drift by minor units.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
from decimal import Decimal, ROUND_HALF_EVEN, ROUND_HALF_UP, ROUND_FLOOR, ROUND_CEILING, ROUND_DOWN, ROUND_UP, ROUND_HALF_DOWN
N = 1
observations = []
def solve(items, rate):
    out, cum, prev_floor, day = [], Decimal(0), 0, None
    r = Decimal(rate)
    for d, a in items:
        if d != day:
            day, cum = d, Decimal(0)
        cum += Decimal(a) * r
        f = int(cum.to_integral_value(rounding=ROUND_FLOOR))
        out.append(f - prev_floor)
        prev_floor = f
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression previous-floor-reset 1', ([['d1', 7], ['d2', 1]], '0.5'), [3, 0]),
  ('regression previous-floor-reset 2', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('partial repair guard 2', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]), ('control: empty', ([], '1.5'), [])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', 186], ['2026-03-01', -5], ['2026-03-02', 8], ['2026-03-02', 154]], '0.3542'), [65, -1, 2, 55]),
  ('regression previous-floor-reset 2',
   ([['2026-03-01', 263], ['2026-03-01', 239], ['2026-03-01', 228], ['2026-03-01', -26], ['2026-03-02', 231]], '29.57'),
   [7776, 7068, 6742, -769, 6830]),
  ('partial repair guard 1',
   ([['2026-03-01', -18], ['2026-03-01', 240], ['2026-03-02', -19], ['2026-03-02', 81], ['2026-03-02', 129],
     ['2026-03-02', 231]],
    '0.2472'),
   [-5, 59, -5, 20, 32, 57]),
  ('partial repair guard 2',
   ([['2026-03-02', 92], ['2026-03-03', 36], ['2026-03-03', -15], ['2026-04-01', 46], ['2026-04-01', 50],
     ['2026-04-01', 95]],
    '4.346'),
   [399, 156, -65, 199, 218, 413]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]),
  ('control: month change', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('control: empty', ([], '1.5'), []),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', -18], ['2026-03-01', 240], ['2026-03-02', -19], ['2026-03-02', 81], ['2026-03-02', 129],
     ['2026-03-02', 231]],
    '0.2472'),
   [-5, 59, -5, 20, 32, 57]),
  ('regression previous-floor-reset 2', ([['2026-03-02', 294], ['2026-03-03', 199]], '0.0860'), [25, 17]),
  ('partial repair guard 1',
   ([['2026-03-02', 62], ['2026-03-02', 120], ['2026-03-03', 27], ['2026-03-03', 189]], '0.4750'), [29, 57, 12, 90]),
  ('partial repair guard 2',
   ([['2026-03-01', -26], ['2026-03-01', 4], ['2026-03-01', -3], ['2026-03-02', 57], ['2026-03-02', 131]], '5.53'),
   [-144, 22, -17, 315, 724]),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: day reset', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1])],
 [('regression previous-floor-reset 1',
   ([['2026-03-02', 92], ['2026-03-03', 36], ['2026-03-03', -15], ['2026-04-01', 46], ['2026-04-01', 50],
     ['2026-04-01', 95]],
    '4.346'),
   [399, 156, -65, 199, 218, 413]),
  ('regression previous-floor-reset 2',
   ([['2026-03-02', 62], ['2026-03-02', 120], ['2026-03-03', 27], ['2026-03-03', 189]], '0.4750'), [29, 57, 12, 90]),
  ('partial repair guard 1',
   ([['2026-03-01', 59], ['2026-03-02', 159], ['2026-03-02', 71], ['2026-03-03', 89]], '26.15'),
   [1542, 4157, 1857, 2327]),
  ('partial repair guard 2', ([['2026-03-01', -26], ['2026-03-02', 215]], '27.52'), [-716, 5916]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]),
  ('control: month change', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('control: empty', ([], '1.5'), [])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', -26], ['2026-03-01', 4], ['2026-03-01', -3], ['2026-03-02', 57], ['2026-03-02', 131]], '5.53'),
   [-144, 22, -17, 315, 724]),
  ('regression previous-floor-reset 2', ([['2026-03-01', 197], ['2026-03-02', 286], ['2026-03-02', 74]], '29.61'),
   [5833, 8468, 2191]),
  ('partial repair guard 1',
   ([['2026-03-02', 39], ['2026-03-02', 262], ['2026-03-02', -11], ['2026-03-03', 235], ['2026-03-03', -7],
     ['2026-03-03', 97]],
    '4.821'),
   [188, 1263, -53, 1132, -33, 467]),
  ('partial repair guard 2',
   ([['2026-03-01', 42], ['2026-03-02', 162], ['2026-03-02', 1], ['2026-03-02', 28], ['2026-03-03', 127],
     ['2026-03-03', -4]],
    '0.0325'),
   [1, 5, 0, 1, 4, -1]),
  ('control: empty', ([], '1.5'), []),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: day reset', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1])]]
for label, args, expected in cases[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
regression previous-floor-reset 1	`[3, -3]`	`[3, 0]`	Failed
regression previous-floor-reset 2	`[1, 0]`	`[1, 1]`	Failed
partial repair guard 2	`[0, 0, 1]`	`[0, 0, 1]`	Passed
control: three micro postings	`[0, 0, 1]`	`[0, 0, 1]`	Passed
control: reversal	`[2, -1]`	`[2, -1]`	Passed
control: single large	`[11375]`	`[11375]`	Passed
control: empty	`[]`	`[]`	Passed

SHA-256 / cdac0b068656c9d4af30d7535889b4df845c841e03c0b15144b49f41d6859d70

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
from decimal import Decimal, ROUND_HALF_EVEN, ROUND_HALF_UP, ROUND_FLOOR, ROUND_CEILING, ROUND_DOWN, ROUND_UP, ROUND_HALF_DOWN
N = 1
observations = []
def solve(items, rate):
    out, cum, prev_floor, day = [], Decimal(0), 0, None
    r = Decimal(rate)
    for d, a in items:
        if d != day:
            day, cum, prev_floor = d, cum - prev_floor, 0
        cum += Decimal(a) * r
        f = int(cum.to_integral_value(rounding=ROUND_FLOOR))
        out.append(f - prev_floor)
        prev_floor = f
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression previous-floor-reset 1', ([['d1', 7], ['d2', 1]], '0.5'), [3, 0]),
  ('regression previous-floor-reset 2', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('partial repair guard 2', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]), ('control: empty', ([], '1.5'), [])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', 186], ['2026-03-01', -5], ['2026-03-02', 8], ['2026-03-02', 154]], '0.3542'), [65, -1, 2, 55]),
  ('regression previous-floor-reset 2',
   ([['2026-03-01', 263], ['2026-03-01', 239], ['2026-03-01', 228], ['2026-03-01', -26], ['2026-03-02', 231]], '29.57'),
   [7776, 7068, 6742, -769, 6830]),
  ('partial repair guard 1',
   ([['2026-03-01', -18], ['2026-03-01', 240], ['2026-03-02', -19], ['2026-03-02', 81], ['2026-03-02', 129],
     ['2026-03-02', 231]],
    '0.2472'),
   [-5, 59, -5, 20, 32, 57]),
  ('partial repair guard 2',
   ([['2026-03-02', 92], ['2026-03-03', 36], ['2026-03-03', -15], ['2026-04-01', 46], ['2026-04-01', 50],
     ['2026-04-01', 95]],
    '4.346'),
   [399, 156, -65, 199, 218, 413]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]),
  ('control: month change', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('control: empty', ([], '1.5'), []),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', -18], ['2026-03-01', 240], ['2026-03-02', -19], ['2026-03-02', 81], ['2026-03-02', 129],
     ['2026-03-02', 231]],
    '0.2472'),
   [-5, 59, -5, 20, 32, 57]),
  ('regression previous-floor-reset 2', ([['2026-03-02', 294], ['2026-03-03', 199]], '0.0860'), [25, 17]),
  ('partial repair guard 1',
   ([['2026-03-02', 62], ['2026-03-02', 120], ['2026-03-03', 27], ['2026-03-03', 189]], '0.4750'), [29, 57, 12, 90]),
  ('partial repair guard 2',
   ([['2026-03-01', -26], ['2026-03-01', 4], ['2026-03-01', -3], ['2026-03-02', 57], ['2026-03-02', 131]], '5.53'),
   [-144, 22, -17, 315, 724]),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: day reset', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1])],
 [('regression previous-floor-reset 1',
   ([['2026-03-02', 92], ['2026-03-03', 36], ['2026-03-03', -15], ['2026-04-01', 46], ['2026-04-01', 50],
     ['2026-04-01', 95]],
    '4.346'),
   [399, 156, -65, 199, 218, 413]),
  ('regression previous-floor-reset 2',
   ([['2026-03-02', 62], ['2026-03-02', 120], ['2026-03-03', 27], ['2026-03-03', 189]], '0.4750'), [29, 57, 12, 90]),
  ('partial repair guard 1',
   ([['2026-03-01', 59], ['2026-03-02', 159], ['2026-03-02', 71], ['2026-03-03', 89]], '26.15'),
   [1542, 4157, 1857, 2327]),
  ('partial repair guard 2', ([['2026-03-01', -26], ['2026-03-02', 215]], '27.52'), [-716, 5916]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]),
  ('control: month change', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('control: empty', ([], '1.5'), [])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', -26], ['2026-03-01', 4], ['2026-03-01', -3], ['2026-03-02', 57], ['2026-03-02', 131]], '5.53'),
   [-144, 22, -17, 315, 724]),
  ('regression previous-floor-reset 2', ([['2026-03-01', 197], ['2026-03-02', 286], ['2026-03-02', 74]], '29.61'),
   [5833, 8468, 2191]),
  ('partial repair guard 1',
   ([['2026-03-02', 39], ['2026-03-02', 262], ['2026-03-02', -11], ['2026-03-03', 235], ['2026-03-03', -7],
     ['2026-03-03', 97]],
    '4.821'),
   [188, 1263, -53, 1132, -33, 467]),
  ('partial repair guard 2',
   ([['2026-03-01', 42], ['2026-03-02', 162], ['2026-03-02', 1], ['2026-03-02', 28], ['2026-03-03', 127],
     ['2026-03-03', -4]],
    '0.0325'),
   [1, 5, 0, 1, 4, -1]),
  ('control: empty', ([], '1.5'), []),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: day reset', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1])]]
for label, args, expected in cases[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
regression previous-floor-reset 1	`[3, 1]`	`[3, 0]`	Failed
regression previous-floor-reset 2	`[1, 1]`	`[1, 1]`	Passed
partial repair guard 2	`[0, 1, 0]`	`[0, 0, 1]`	Failed
control: three micro postings	`[0, 0, 1]`	`[0, 0, 1]`	Passed
control: reversal	`[2, -1]`	`[2, -1]`	Passed
control: single large	`[11375]`	`[11375]`	Passed
control: empty	`[]`	`[]`	Passed

SHA-256 / 254dbf2cd96b6db1a62ee47f524ade3eb5b63fc6d35395f8c6f03969667ded49

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
from decimal import Decimal, ROUND_HALF_EVEN, ROUND_HALF_UP, ROUND_FLOOR, ROUND_CEILING, ROUND_DOWN, ROUND_UP, ROUND_HALF_DOWN
N = 1
observations = []
def solve(items, rate):
    out, cum, prev_floor, day = [], Decimal(0), 0, None
    r = Decimal(rate)
    for d, a in items:
        if d != day:
            day, cum, prev_floor = d, Decimal(0), 0
        cum += Decimal(a) * r
        f = int(cum.to_integral_value(rounding=ROUND_FLOOR))
        out.append(f - prev_floor)
        prev_floor = f
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression previous-floor-reset 1', ([['d1', 7], ['d2', 1]], '0.5'), [3, 0]),
  ('regression previous-floor-reset 2', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('partial repair guard 2', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]), ('control: empty', ([], '1.5'), [])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', 186], ['2026-03-01', -5], ['2026-03-02', 8], ['2026-03-02', 154]], '0.3542'), [65, -1, 2, 55]),
  ('regression previous-floor-reset 2',
   ([['2026-03-01', 263], ['2026-03-01', 239], ['2026-03-01', 228], ['2026-03-01', -26], ['2026-03-02', 231]], '29.57'),
   [7776, 7068, 6742, -769, 6830]),
  ('partial repair guard 1',
   ([['2026-03-01', -18], ['2026-03-01', 240], ['2026-03-02', -19], ['2026-03-02', 81], ['2026-03-02', 129],
     ['2026-03-02', 231]],
    '0.2472'),
   [-5, 59, -5, 20, 32, 57]),
  ('partial repair guard 2',
   ([['2026-03-02', 92], ['2026-03-03', 36], ['2026-03-03', -15], ['2026-04-01', 46], ['2026-04-01', 50],
     ['2026-04-01', 95]],
    '4.346'),
   [399, 156, -65, 199, 218, 413]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]),
  ('control: month change', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('control: empty', ([], '1.5'), []),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', -18], ['2026-03-01', 240], ['2026-03-02', -19], ['2026-03-02', 81], ['2026-03-02', 129],
     ['2026-03-02', 231]],
    '0.2472'),
   [-5, 59, -5, 20, 32, 57]),
  ('regression previous-floor-reset 2', ([['2026-03-02', 294], ['2026-03-03', 199]], '0.0860'), [25, 17]),
  ('partial repair guard 1',
   ([['2026-03-02', 62], ['2026-03-02', 120], ['2026-03-03', 27], ['2026-03-03', 189]], '0.4750'), [29, 57, 12, 90]),
  ('partial repair guard 2',
   ([['2026-03-01', -26], ['2026-03-01', 4], ['2026-03-01', -3], ['2026-03-02', 57], ['2026-03-02', 131]], '5.53'),
   [-144, 22, -17, 315, 724]),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: day reset', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1])],
 [('regression previous-floor-reset 1',
   ([['2026-03-02', 92], ['2026-03-03', 36], ['2026-03-03', -15], ['2026-04-01', 46], ['2026-04-01', 50],
     ['2026-04-01', 95]],
    '4.346'),
   [399, 156, -65, 199, 218, 413]),
  ('regression previous-floor-reset 2',
   ([['2026-03-02', 62], ['2026-03-02', 120], ['2026-03-03', 27], ['2026-03-03', 189]], '0.4750'), [29, 57, 12, 90]),
  ('partial repair guard 1',
   ([['2026-03-01', 59], ['2026-03-02', 159], ['2026-03-02', 71], ['2026-03-03', 89]], '26.15'),
   [1542, 4157, 1857, 2327]),
  ('partial repair guard 2', ([['2026-03-01', -26], ['2026-03-02', 215]], '27.52'), [-716, 5916]),
  ('control: reversal', ([['d1', 5], ['d1', -3]], '0.5'), [2, -1]),
  ('control: single large', ([['2026-03-01', 12345]], '0.9215'), [11375]),
  ('control: month change', ([['2026-03-31', 3], ['2026-04-01', 3]], '0.35'), [1, 1]),
  ('control: empty', ([], '1.5'), [])],
 [('regression previous-floor-reset 1',
   ([['2026-03-01', -26], ['2026-03-01', 4], ['2026-03-01', -3], ['2026-03-02', 57], ['2026-03-02', 131]], '5.53'),
   [-144, 22, -17, 315, 724]),
  ('regression previous-floor-reset 2', ([['2026-03-01', 197], ['2026-03-02', 286], ['2026-03-02', 74]], '29.61'),
   [5833, 8468, 2191]),
  ('partial repair guard 1',
   ([['2026-03-02', 39], ['2026-03-02', 262], ['2026-03-02', -11], ['2026-03-03', 235], ['2026-03-03', -7],
     ['2026-03-03', 97]],
    '4.821'),
   [188, 1263, -53, 1132, -33, 467]),
  ('partial repair guard 2',
   ([['2026-03-01', 42], ['2026-03-02', 162], ['2026-03-02', 1], ['2026-03-02', 28], ['2026-03-03', 127],
     ['2026-03-03', -4]],
    '0.0325'),
   [1, 5, 0, 1, 4, -1]),
  ('control: empty', ([], '1.5'), []),
  ('control: negative first', ([['d1', -1], ['d1', -1], ['d1', 2]], '0.3'), [-1, 0, 1]),
  ('control: three micro postings', ([['d1', 1], ['d1', 1], ['d1', 1]], '0.4'), [0, 0, 1]),
  ('control: day reset', ([['d1', 1], ['d2', 1], ['d2', 1]], '0.6'), [0, 0, 1])]]
for label, args, expected in cases[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
regression previous-floor-reset 1	`[3, 0]`	`[3, 0]`	Passed
regression previous-floor-reset 2	`[1, 1]`	`[1, 1]`	Passed
partial repair guard 2	`[0, 0, 1]`	`[0, 0, 1]`	Passed
control: three micro postings	`[0, 0, 1]`	`[0, 0, 1]`	Passed
control: reversal	`[2, -1]`	`[2, -1]`	Passed
control: single large	`[11375]`	`[11375]`	Passed
control: empty	`[]`	`[]`	Passed

SHA-256 / 5266517c8b2446a2c34141dd96e4837a232b69f18947ebf5f6a962e17b8f2f14

Verification & scope

A deterministic, bounded teaching model with a stipulated toy contract; it makes no claim of conformance to any real regulation, standard, or institution's rules. 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 2026-09-29T14:47:02.461880+00:00.

Case digest / 01746861227996b29e9136570ec5031c06ee2bf022f7ce0781ebe9edf4cef219