FAILURE MAP
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FA-91886 / PLC ladder logic scan cycles / Open access

TOF never expires once ACC is clamped · case 01

The off-delay output stays on forever after the rung drops.

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

ROOT CAUSE

Expiry uses acc > preset while the accumulator is clamped at preset.

VERIFIED REPAIR

Clear DN when acc >= preset.

Unsuccessful approach: Requiring a nonzero accumulator leaves a zero-preset off-delay latched on.

Case contract

Off-delay timer (TOF) evaluated once per scan; scans is a list of [rung_in, elapsed_ms]. At power-up the timer is expired (ACC = preset, DN false). A true rung clears ACC and sets DN. After the rung drops, ACC accumulates each later false scan's elapsed time (the true-to-false scan itself is not credited), clamped at preset, and DN clears when ACC >= preset. TT is DN and not rung_in. Return [DN, TT, ACC] per scan.

Why this case matters

Ladder programs are executed as repeated scans; each defect here changes what a rung, timer, counter or data-table instruction reports on a particular scan, which is how commissioning and field faults are actually observed.

1 / The failure

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

N = 1
observations = []
def solve(preset, scans):
    acc = preset
    dn = False
    prev = False
    out = []
    for rung_in, dt in scans:
        rung_in = bool(rung_in)
        if rung_in:
            acc = 0
            dn = True
        elif dn:
            if not prev:
                acc = min(preset, acc + dt)
            if acc > preset:
                dn = False
        tt = dn and not rung_in
        prev = rung_in
        out.append([dn, tt, acc])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: scenario 6',
   [0, [[False, 30], [False, 50], [True, 20], [True, 20], [False, 30], [False, 30], [True, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['control: scenario 1',
   [60, [[False, 70], [True, 10], [True, 70], [True, 10], [False, 70], [False, 10], [True, 10], [False, 30]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0]]],
  ['regression: scenario 2',
   [60, [[False, 30], [True, 50], [True, 20], [True, 30], [True, 70], [False, 50], [False, 50], [False, 70]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 50],
    [False, False, 60]]],
  ['regression: scenario 3',
   [40,
    [[True, 70],
     [True, 0],
     [False, 50],
     [True, 30],
     [False, 0],
     [False, 50],
     [False, 30],
     [False, 50],
     [False, 10],
     [True, 20]]],
   [[True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [True, False, 0]]]],
 [['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [0, [[False, 30], [True, 20], [True, 30], [False, 50], [True, 0], [True, 50], [True, 50]]],
   [[False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: scenario 2',
   [0, [[False, 10], [True, 0], [True, 70], [False, 0], [True, 70], [False, 20], [False, 10]]],
   [[False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['control: scenario 3',
   [150,
    [[False, 50],
     [False, 10],
     [False, 0],
     [False, 50],
     [True, 50],
     [False, 70],
     [False, 10],
     [True, 70],
     [False, 50],
     [False, 70],
     [False, 20],
     [True, 50],
     [False, 0],
     [True, 30]]],
   [[False, False, 150],
    [False, False, 150],
    [False, False, 150],
    [False, False, 150],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0],
    [True, True, 70],
    [True, True, 90],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0]]],
  ['regression: scenario 4',
   [60,
    [[False, 0],
     [False, 10],
     [True, 20],
     [False, 20],
     [False, 0],
     [False, 0],
     [True, 50],
     [True, 20],
     [True, 10],
     [True, 0],
     [True, 10],
     [False, 20],
     [False, 70]]],
   [[False, False, 60],
    [False, False, 60],
    [True, False, 0],
    [True, True, 0],
    [True, True, 0],
    [True, True, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 60]]]],
 [['regression: scenario 1',
   [0,
    [[False, 50],
     [True, 10],
     [False, 0],
     [True, 20],
     [False, 70],
     [False, 50],
     [True, 70],
     [False, 10],
     [False, 10],
     [False, 20],
     [True, 70]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['regression: scenario 3',
   [0,
    [[False, 10],
     [False, 10],
     [False, 70],
     [False, 30],
     [True, 50],
     [False, 10],
     [False, 0],
     [True, 20],
     [False, 70],
     [True, 10],
     [False, 70],
     [True, 20],
     [False, 70],
     [True, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 2',
   [0,
    [[False, 30],
     [True, 50],
     [False, 50],
     [True, 0],
     [True, 10],
     [True, 10],
     [False, 10],
     [False, 50],
     [False, 10]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['regression: scenario 4',
   [0,
    [[False, 30],
     [True, 0],
     [False, 70],
     [False, 0],
     [True, 20],
     [False, 50],
     [False, 0],
     [False, 10],
     [False, 20],
     [False, 50],
     [False, 50]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0]]]],
 [['regression: scenario 5',
   [0, [[False, 50], [False, 50], [True, 70], [True, 10], [False, 30], [False, 50], [True, 70]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['regression: scenario 26',
   [0,
    [[False, 20],
     [False, 70],
     [True, 30],
     [True, 10],
     [False, 20],
     [True, 0],
     [True, 50],
     [False, 50],
     [True, 20],
     [False, 70],
     [False, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [40, [[True, 70], [True, 20], [True, 20], [False, 30], [False, 30], [False, 0], [False, 70], [False, 20]]],
   [[True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, True, 30],
    [False, False, 40],
    [False, False, 40]]],
  ['control: scenario 2',
   [100,
    [[False, 30],
     [False, 20],
     [True, 20],
     [True, 10],
     [True, 70],
     [False, 20],
     [False, 10],
     [True, 20],
     [False, 0],
     [True, 0],
     [True, 0]]],
   [[False, False, 100],
    [False, False, 100],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, False, 0]]]],
 [['regression: scenario 4',
   [40,
    [[False, 50],
     [True, 10],
     [False, 20],
     [False, 20],
     [True, 70],
     [False, 10],
     [True, 10],
     [False, 50],
     [False, 70],
     [False, 30],
     [False, 20],
     [False, 0]]],
   [[False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40]]],
  ['regression: scenario 35',
   [0,
    [[True, 20],
     [False, 50],
     [True, 30],
     [False, 30],
     [True, 20],
     [True, 70],
     [False, 30],
     [False, 50],
     [True, 0]]],
   [[True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [40,
    [[True, 70], [True, 20], [False, 50], [False, 20], [False, 50], [False, 50], [False, 50], [False, 0]]],
   [[True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40]]],
  ['control: scenario 2',
   [40,
    [[False, 70],
     [True, 70],
     [False, 50],
     [True, 70],
     [False, 10],
     [False, 30],
     [True, 0],
     [True, 50],
     [False, 0],
     [False, 30]]],
   [[False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30]]]]]
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 fixtureActualExpectedOutcome
regression: zero preset drop[[True, False, 0], [True, True, 0], [True, True, 0]][[True, False, 0], [False, False, 0], [False, False, 0]]Failed
regression: scenario 6[[False, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 0], [True, False, 0]][[False, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [False, False, 0], [False, False, 0], [True, False, 0]]Failed
control: power-up with false rung[[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]][[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]Passed
control: re-energized mid delay[[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]][[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]]Passed
regression: exact expiry[[True, False, 0], [True, True, 0], [True, True, 30], [True, True, 60], [True, True, 60]][[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]Failed
control: scenario 1[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]]Passed
regression: scenario 2[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50], [True, True, 60]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50], [False, False, 60]]Failed
regression: scenario 3[[True, False, 0], [True, False, 0], [True, True, 0], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 40], [True, True, 40], [True, True, 40], [True, False, 0]][[True, False, 0], [True, False, 0], [True, True, 0], [True, False, 0], [True, True, 0], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [True, False, 0]]Failed

SHA-256 / 72a525ad23d6e826dc9248feced0bea31ccd1bb2d591d178c4efa2b9842d283e

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(preset, scans):
    acc = preset
    dn = False
    prev = False
    out = []
    for rung_in, dt in scans:
        rung_in = bool(rung_in)
        if rung_in:
            acc = 0
            dn = True
        elif dn:
            if not prev:
                acc = min(preset, acc + dt)
            if acc >= preset and acc > 0:
                dn = False
        tt = dn and not rung_in
        prev = rung_in
        out.append([dn, tt, acc])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: scenario 6',
   [0, [[False, 30], [False, 50], [True, 20], [True, 20], [False, 30], [False, 30], [True, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['control: scenario 1',
   [60, [[False, 70], [True, 10], [True, 70], [True, 10], [False, 70], [False, 10], [True, 10], [False, 30]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0]]],
  ['regression: scenario 2',
   [60, [[False, 30], [True, 50], [True, 20], [True, 30], [True, 70], [False, 50], [False, 50], [False, 70]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 50],
    [False, False, 60]]],
  ['regression: scenario 3',
   [40,
    [[True, 70],
     [True, 0],
     [False, 50],
     [True, 30],
     [False, 0],
     [False, 50],
     [False, 30],
     [False, 50],
     [False, 10],
     [True, 20]]],
   [[True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [True, False, 0]]]],
 [['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [0, [[False, 30], [True, 20], [True, 30], [False, 50], [True, 0], [True, 50], [True, 50]]],
   [[False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: scenario 2',
   [0, [[False, 10], [True, 0], [True, 70], [False, 0], [True, 70], [False, 20], [False, 10]]],
   [[False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['control: scenario 3',
   [150,
    [[False, 50],
     [False, 10],
     [False, 0],
     [False, 50],
     [True, 50],
     [False, 70],
     [False, 10],
     [True, 70],
     [False, 50],
     [False, 70],
     [False, 20],
     [True, 50],
     [False, 0],
     [True, 30]]],
   [[False, False, 150],
    [False, False, 150],
    [False, False, 150],
    [False, False, 150],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0],
    [True, True, 70],
    [True, True, 90],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0]]],
  ['regression: scenario 4',
   [60,
    [[False, 0],
     [False, 10],
     [True, 20],
     [False, 20],
     [False, 0],
     [False, 0],
     [True, 50],
     [True, 20],
     [True, 10],
     [True, 0],
     [True, 10],
     [False, 20],
     [False, 70]]],
   [[False, False, 60],
    [False, False, 60],
    [True, False, 0],
    [True, True, 0],
    [True, True, 0],
    [True, True, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 60]]]],
 [['regression: scenario 1',
   [0,
    [[False, 50],
     [True, 10],
     [False, 0],
     [True, 20],
     [False, 70],
     [False, 50],
     [True, 70],
     [False, 10],
     [False, 10],
     [False, 20],
     [True, 70]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['regression: scenario 3',
   [0,
    [[False, 10],
     [False, 10],
     [False, 70],
     [False, 30],
     [True, 50],
     [False, 10],
     [False, 0],
     [True, 20],
     [False, 70],
     [True, 10],
     [False, 70],
     [True, 20],
     [False, 70],
     [True, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 2',
   [0,
    [[False, 30],
     [True, 50],
     [False, 50],
     [True, 0],
     [True, 10],
     [True, 10],
     [False, 10],
     [False, 50],
     [False, 10]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['regression: scenario 4',
   [0,
    [[False, 30],
     [True, 0],
     [False, 70],
     [False, 0],
     [True, 20],
     [False, 50],
     [False, 0],
     [False, 10],
     [False, 20],
     [False, 50],
     [False, 50]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0]]]],
 [['regression: scenario 5',
   [0, [[False, 50], [False, 50], [True, 70], [True, 10], [False, 30], [False, 50], [True, 70]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['regression: scenario 26',
   [0,
    [[False, 20],
     [False, 70],
     [True, 30],
     [True, 10],
     [False, 20],
     [True, 0],
     [True, 50],
     [False, 50],
     [True, 20],
     [False, 70],
     [False, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [40, [[True, 70], [True, 20], [True, 20], [False, 30], [False, 30], [False, 0], [False, 70], [False, 20]]],
   [[True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, True, 30],
    [False, False, 40],
    [False, False, 40]]],
  ['control: scenario 2',
   [100,
    [[False, 30],
     [False, 20],
     [True, 20],
     [True, 10],
     [True, 70],
     [False, 20],
     [False, 10],
     [True, 20],
     [False, 0],
     [True, 0],
     [True, 0]]],
   [[False, False, 100],
    [False, False, 100],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, False, 0]]]],
 [['regression: scenario 4',
   [40,
    [[False, 50],
     [True, 10],
     [False, 20],
     [False, 20],
     [True, 70],
     [False, 10],
     [True, 10],
     [False, 50],
     [False, 70],
     [False, 30],
     [False, 20],
     [False, 0]]],
   [[False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40]]],
  ['regression: scenario 35',
   [0,
    [[True, 20],
     [False, 50],
     [True, 30],
     [False, 30],
     [True, 20],
     [True, 70],
     [False, 30],
     [False, 50],
     [True, 0]]],
   [[True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [40,
    [[True, 70], [True, 20], [False, 50], [False, 20], [False, 50], [False, 50], [False, 50], [False, 0]]],
   [[True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40]]],
  ['control: scenario 2',
   [40,
    [[False, 70],
     [True, 70],
     [False, 50],
     [True, 70],
     [False, 10],
     [False, 30],
     [True, 0],
     [True, 50],
     [False, 0],
     [False, 30]]],
   [[False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30]]]]]
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 fixtureActualExpectedOutcome
regression: zero preset drop[[True, False, 0], [True, True, 0], [True, True, 0]][[True, False, 0], [False, False, 0], [False, False, 0]]Failed
regression: scenario 6[[False, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 0], [True, False, 0]][[False, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [False, False, 0], [False, False, 0], [True, False, 0]]Failed
control: power-up with false rung[[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]][[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]Passed
control: re-energized mid delay[[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]][[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]]Passed
regression: exact expiry[[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]][[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]Passed
control: scenario 1[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]]Passed
regression: scenario 2[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50], [False, False, 60]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50], [False, False, 60]]Passed
regression: scenario 3[[True, False, 0], [True, False, 0], [True, True, 0], [True, False, 0], [True, True, 0], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [True, False, 0]][[True, False, 0], [True, False, 0], [True, True, 0], [True, False, 0], [True, True, 0], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [True, False, 0]]Passed

SHA-256 / 8598a7e4aa420db73b7e29d450a71b464b35be282f49ef9419a13bdc57c03a6c

3 / The verified repair

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

N = 1
observations = []
def solve(preset, scans):
    acc = preset
    dn = False
    prev = False
    out = []
    for rung_in, dt in scans:
        rung_in = bool(rung_in)
        if rung_in:
            acc = 0
            dn = True
        elif dn:
            if not prev:
                acc = min(preset, acc + dt)
            if acc >= preset:
                dn = False
        tt = dn and not rung_in
        prev = rung_in
        out.append([dn, tt, acc])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: scenario 6',
   [0, [[False, 30], [False, 50], [True, 20], [True, 20], [False, 30], [False, 30], [True, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['control: scenario 1',
   [60, [[False, 70], [True, 10], [True, 70], [True, 10], [False, 70], [False, 10], [True, 10], [False, 30]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0]]],
  ['regression: scenario 2',
   [60, [[False, 30], [True, 50], [True, 20], [True, 30], [True, 70], [False, 50], [False, 50], [False, 70]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 50],
    [False, False, 60]]],
  ['regression: scenario 3',
   [40,
    [[True, 70],
     [True, 0],
     [False, 50],
     [True, 30],
     [False, 0],
     [False, 50],
     [False, 30],
     [False, 50],
     [False, 10],
     [True, 20]]],
   [[True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [True, False, 0]]]],
 [['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [0, [[False, 30], [True, 20], [True, 30], [False, 50], [True, 0], [True, 50], [True, 50]]],
   [[False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: scenario 2',
   [0, [[False, 10], [True, 0], [True, 70], [False, 0], [True, 70], [False, 20], [False, 10]]],
   [[False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['control: scenario 3',
   [150,
    [[False, 50],
     [False, 10],
     [False, 0],
     [False, 50],
     [True, 50],
     [False, 70],
     [False, 10],
     [True, 70],
     [False, 50],
     [False, 70],
     [False, 20],
     [True, 50],
     [False, 0],
     [True, 30]]],
   [[False, False, 150],
    [False, False, 150],
    [False, False, 150],
    [False, False, 150],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0],
    [True, True, 70],
    [True, True, 90],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0]]],
  ['regression: scenario 4',
   [60,
    [[False, 0],
     [False, 10],
     [True, 20],
     [False, 20],
     [False, 0],
     [False, 0],
     [True, 50],
     [True, 20],
     [True, 10],
     [True, 0],
     [True, 10],
     [False, 20],
     [False, 70]]],
   [[False, False, 60],
    [False, False, 60],
    [True, False, 0],
    [True, True, 0],
    [True, True, 0],
    [True, True, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 60]]]],
 [['regression: scenario 1',
   [0,
    [[False, 50],
     [True, 10],
     [False, 0],
     [True, 20],
     [False, 70],
     [False, 50],
     [True, 70],
     [False, 10],
     [False, 10],
     [False, 20],
     [True, 70]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['regression: scenario 3',
   [0,
    [[False, 10],
     [False, 10],
     [False, 70],
     [False, 30],
     [True, 50],
     [False, 10],
     [False, 0],
     [True, 20],
     [False, 70],
     [True, 10],
     [False, 70],
     [True, 20],
     [False, 70],
     [True, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 2',
   [0,
    [[False, 30],
     [True, 50],
     [False, 50],
     [True, 0],
     [True, 10],
     [True, 10],
     [False, 10],
     [False, 50],
     [False, 10]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['regression: scenario 4',
   [0,
    [[False, 30],
     [True, 0],
     [False, 70],
     [False, 0],
     [True, 20],
     [False, 50],
     [False, 0],
     [False, 10],
     [False, 20],
     [False, 50],
     [False, 50]]],
   [[False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0]]]],
 [['regression: scenario 5',
   [0, [[False, 50], [False, 50], [True, 70], [True, 10], [False, 30], [False, 50], [True, 70]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['regression: scenario 26',
   [0,
    [[False, 20],
     [False, 70],
     [True, 30],
     [True, 10],
     [False, 20],
     [True, 0],
     [True, 50],
     [False, 50],
     [True, 20],
     [False, 70],
     [False, 0]]],
   [[False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [40, [[True, 70], [True, 20], [True, 20], [False, 30], [False, 30], [False, 0], [False, 70], [False, 20]]],
   [[True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, True, 30],
    [False, False, 40],
    [False, False, 40]]],
  ['control: scenario 2',
   [100,
    [[False, 30],
     [False, 20],
     [True, 20],
     [True, 10],
     [True, 70],
     [False, 20],
     [False, 10],
     [True, 20],
     [False, 0],
     [True, 0],
     [True, 0]]],
   [[False, False, 100],
    [False, False, 100],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, False, 0]]]],
 [['regression: scenario 4',
   [40,
    [[False, 50],
     [True, 10],
     [False, 20],
     [False, 20],
     [True, 70],
     [False, 10],
     [True, 10],
     [False, 50],
     [False, 70],
     [False, 30],
     [False, 20],
     [False, 0]]],
   [[False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40]]],
  ['regression: scenario 35',
   [0,
    [[True, 20],
     [False, 50],
     [True, 30],
     [False, 30],
     [True, 20],
     [True, 70],
     [False, 30],
     [False, 50],
     [True, 0]]],
   [[True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0]]],
  ['control: power-up with false rung',
   [60, [[False, 20], [False, 20], [False, 20], [True, 10]]],
   [[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]],
  ['control: re-energized mid delay',
   [100, [[True, 10], [False, 40], [False, 40], [True, 40], [False, 40], [False, 40], [False, 40]]],
   [[True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 40],
    [True, True, 80]]],
  ['regression: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['regression: exact expiry',
   [60, [[True, 10], [False, 30], [False, 30], [False, 30], [False, 30]]],
   [[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]],
  ['regression: scenario 1',
   [40,
    [[True, 70], [True, 20], [False, 50], [False, 20], [False, 50], [False, 50], [False, 50], [False, 0]]],
   [[True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40],
    [False, False, 40]]],
  ['control: scenario 2',
   [40,
    [[False, 70],
     [True, 70],
     [False, 50],
     [True, 70],
     [False, 10],
     [False, 30],
     [True, 0],
     [True, 50],
     [False, 0],
     [False, 30]]],
   [[False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30]]]]]
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 fixtureActualExpectedOutcome
regression: zero preset drop[[True, False, 0], [False, False, 0], [False, False, 0]][[True, False, 0], [False, False, 0], [False, False, 0]]Passed
regression: scenario 6[[False, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [False, False, 0], [False, False, 0], [True, False, 0]][[False, False, 0], [False, False, 0], [True, False, 0], [True, False, 0], [False, False, 0], [False, False, 0], [True, False, 0]]Passed
control: power-up with false rung[[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]][[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]Passed
control: re-energized mid delay[[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]][[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]]Passed
regression: exact expiry[[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]][[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]Passed
control: scenario 1[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]]Passed
regression: scenario 2[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50], [False, False, 60]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50], [False, False, 60]]Passed
regression: scenario 3[[True, False, 0], [True, False, 0], [True, True, 0], [True, False, 0], [True, True, 0], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [True, False, 0]][[True, False, 0], [True, False, 0], [True, True, 0], [True, False, 0], [True, True, 0], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [True, False, 0]]Passed

SHA-256 / fcc9cda6238d7bcb8ea6e22ae0e038454cfb235beeef3cd47d4dd67daea11971

Verification & scope

A deterministic bounded teaching model of one PLC instruction or rung pattern evaluated scan by scan. The stated contract is a stipulated toy convention, not a claim of conformance to any vendor controller or IEC 61131-3 runtime. 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 2026-09-29T14:51:40.345823+00:00.

Case digest / 3c360b0bc6453af9e6d4c5498a7668197028d17ad68a25d77fdba41e3a350ee4