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FA-91876 / PLC ladder logic scan cycles / Open access

TOF keeps stale delay time when its rung returns · case 01

An off-delay that is re-energized mid-delay then expires early on the next drop.

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

ROOT CAUSE

A true rung sets DN but does not clear the accumulator.

VERIFIED REPAIR

Clear the accumulator on every true-rung scan.

Unsuccessful approach: Clearing ACC only after a completed delay still carries partial delay time across a re-energization.

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:
            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: 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]]],
  ['regression: 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]]],
  ['control: 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',
   [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: scenario 4',
   [100,
    [[False, 30],
     [False, 70],
     [True, 30],
     [False, 30],
     [False, 20],
     [False, 50],
     [False, 70],
     [True, 50],
     [True, 50],
     [False, 20],
     [False, 50]]],
   [[False, False, 100],
    [False, False, 100],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 70],
    [False, False, 100],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 50]]]],
 [['regression: 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: scenario 5',
   [40, [[False, 50], [False, 70], [True, 70], [False, 10], [False, 30], [True, 70]]],
   [[False, False, 40],
    [False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, False, 0]]],
  ['regression: 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: 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]]],
  ['control: 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: 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]]],
  ['regression: 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: 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 14',
   [60,
    [[False, 70],
     [False, 0],
     [True, 0],
     [True, 30],
     [False, 10],
     [False, 20],
     [False, 20],
     [False, 10],
     [True, 0],
     [False, 50],
     [False, 0],
     [False, 20]]],
   [[False, False, 60],
    [False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 40],
    [True, True, 50],
    [True, False, 0],
    [True, True, 0],
    [True, True, 0],
    [True, True, 20]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['control: 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]]],
  ['control: 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]]],
  ['control: 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]]]],
 [['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]]],
  ['regression: scenario 9',
   [150,
    [[True, 10],
     [True, 70],
     [True, 50],
     [False, 50],
     [False, 20],
     [False, 50],
     [True, 50],
     [True, 0],
     [True, 70],
     [False, 30],
     [True, 0],
     [False, 20],
     [False, 10]]],
   [[True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 70],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: 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',
   [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 3',
   [60, [[False, 70], [True, 30], [True, 0], [True, 50], [True, 30], [True, 70], [True, 0]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0]]]],
 [['regression: 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]]],
  ['regression: scenario 10',
   [150,
    [[False, 30],
     [True, 70],
     [False, 20],
     [False, 30],
     [False, 20],
     [False, 10],
     [False, 20],
     [False, 30],
     [True, 70],
     [True, 10],
     [False, 70],
     [False, 20]]],
   [[False, False, 150],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, True, 50],
    [True, True, 60],
    [True, True, 80],
    [True, True, 110],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: 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 3',
   [0,
    [[False, 50],
     [False, 50],
     [False, 20],
     [False, 20],
     [True, 10],
     [True, 50],
     [True, 20],
     [False, 70],
     [False, 30],
     [False, 10],
     [True, 10],
     [True, 70],
     [True, 10],
     [False, 50]]],
   [[False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0]]]]]
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: power-up with false rung[[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 60]][[False, False, 60], [False, False, 60], [False, False, 60], [True, False, 0]]Failed
regression: re-energized mid delay[[True, False, 100], [False, False, 100], [False, False, 100], [True, False, 100], [False, False, 100], [False, False, 100], [False, False, 100]][[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]]Failed
control: zero preset drop[[True, False, 0], [False, False, 0], [False, False, 0]][[True, False, 0], [False, False, 0], [False, False, 0]]Passed
regression: exact expiry[[True, False, 60], [False, False, 60], [False, False, 60], [False, False, 60], [False, False, 60]][[True, False, 0], [True, True, 0], [True, True, 30], [False, False, 60], [False, False, 60]]Failed
regression: scenario 1[[False, False, 60], [True, False, 60], [True, False, 60], [True, False, 60], [False, False, 60], [False, False, 60], [True, False, 60], [False, False, 60]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]]Failed
regression: scenario 2[[False, False, 60], [True, False, 60], [True, False, 60], [True, False, 60], [True, False, 60], [False, False, 60], [False, False, 60], [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]]Failed
regression: scenario 3[[True, False, 40], [True, False, 40], [False, False, 40], [True, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [False, False, 40], [True, False, 40]][[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
regression: scenario 4[[False, False, 100], [False, False, 100], [True, False, 100], [False, False, 100], [False, False, 100], [False, False, 100], [False, False, 100], [True, False, 100], [True, False, 100], [False, False, 100], [False, False, 100]][[False, False, 100], [False, False, 100], [True, False, 0], [True, True, 0], [True, True, 20], [True, True, 70], [False, False, 100], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50]]Failed

SHA-256 / 2f1d68426989b3f6fa1b2526f33029bd649f025efe6eead81508832752e38b4d

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:
            if acc >= preset:
                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: 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]]],
  ['regression: 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]]],
  ['control: 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',
   [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: scenario 4',
   [100,
    [[False, 30],
     [False, 70],
     [True, 30],
     [False, 30],
     [False, 20],
     [False, 50],
     [False, 70],
     [True, 50],
     [True, 50],
     [False, 20],
     [False, 50]]],
   [[False, False, 100],
    [False, False, 100],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 70],
    [False, False, 100],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 50]]]],
 [['regression: 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: scenario 5',
   [40, [[False, 50], [False, 70], [True, 70], [False, 10], [False, 30], [True, 70]]],
   [[False, False, 40],
    [False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, False, 0]]],
  ['regression: 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: 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]]],
  ['control: 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: 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]]],
  ['regression: 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: 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 14',
   [60,
    [[False, 70],
     [False, 0],
     [True, 0],
     [True, 30],
     [False, 10],
     [False, 20],
     [False, 20],
     [False, 10],
     [True, 0],
     [False, 50],
     [False, 0],
     [False, 20]]],
   [[False, False, 60],
    [False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 40],
    [True, True, 50],
    [True, False, 0],
    [True, True, 0],
    [True, True, 0],
    [True, True, 20]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['control: 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]]],
  ['control: 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]]],
  ['control: 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]]]],
 [['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]]],
  ['regression: scenario 9',
   [150,
    [[True, 10],
     [True, 70],
     [True, 50],
     [False, 50],
     [False, 20],
     [False, 50],
     [True, 50],
     [True, 0],
     [True, 70],
     [False, 30],
     [True, 0],
     [False, 20],
     [False, 10]]],
   [[True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 70],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: 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',
   [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 3',
   [60, [[False, 70], [True, 30], [True, 0], [True, 50], [True, 30], [True, 70], [True, 0]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0]]]],
 [['regression: 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]]],
  ['regression: scenario 10',
   [150,
    [[False, 30],
     [True, 70],
     [False, 20],
     [False, 30],
     [False, 20],
     [False, 10],
     [False, 20],
     [False, 30],
     [True, 70],
     [True, 10],
     [False, 70],
     [False, 20]]],
   [[False, False, 150],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, True, 50],
    [True, True, 60],
    [True, True, 80],
    [True, True, 110],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: 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 3',
   [0,
    [[False, 50],
     [False, 50],
     [False, 20],
     [False, 20],
     [True, 10],
     [True, 50],
     [True, 20],
     [False, 70],
     [False, 30],
     [False, 10],
     [True, 10],
     [True, 70],
     [True, 10],
     [False, 50]]],
   [[False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0]]]]]
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: 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
regression: re-energized mid delay[[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 40], [True, True, 40], [True, True, 80], [False, False, 100]][[True, False, 0], [True, True, 0], [True, True, 40], [True, False, 0], [True, True, 0], [True, True, 40], [True, True, 80]]Failed
control: zero preset drop[[True, False, 0], [False, False, 0], [False, False, 0]][[True, False, 0], [False, False, 0], [False, False, 0]]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
regression: scenario 1[[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 10], [True, True, 10]][[False, False, 60], [True, False, 0], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 10], [True, False, 0], [True, True, 0]]Failed
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
regression: scenario 4[[False, False, 100], [False, False, 100], [True, False, 0], [True, True, 0], [True, True, 20], [True, True, 70], [False, False, 100], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50]][[False, False, 100], [False, False, 100], [True, False, 0], [True, True, 0], [True, True, 20], [True, True, 70], [False, False, 100], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50]]Passed

SHA-256 / d28f5b488ca3799dfc00c92607234b82ac4b734a446211f356ffb73600253c37

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: 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]]],
  ['regression: 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]]],
  ['control: 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',
   [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: scenario 4',
   [100,
    [[False, 30],
     [False, 70],
     [True, 30],
     [False, 30],
     [False, 20],
     [False, 50],
     [False, 70],
     [True, 50],
     [True, 50],
     [False, 20],
     [False, 50]]],
   [[False, False, 100],
    [False, False, 100],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 70],
    [False, False, 100],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 50]]]],
 [['regression: 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: scenario 5',
   [40, [[False, 50], [False, 70], [True, 70], [False, 10], [False, 30], [True, 70]]],
   [[False, False, 40],
    [False, False, 40],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, False, 0]]],
  ['regression: 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: 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]]],
  ['control: 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: 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]]],
  ['regression: 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: 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 14',
   [60,
    [[False, 70],
     [False, 0],
     [True, 0],
     [True, 30],
     [False, 10],
     [False, 20],
     [False, 20],
     [False, 10],
     [True, 0],
     [False, 50],
     [False, 0],
     [False, 20]]],
   [[False, False, 60],
    [False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 40],
    [True, True, 50],
    [True, False, 0],
    [True, True, 0],
    [True, True, 0],
    [True, True, 20]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: zero preset drop',
   [0, [[True, 10], [False, 10], [False, 10]]],
   [[True, False, 0], [False, False, 0], [False, False, 0]]],
  ['control: 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]]],
  ['control: 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]]],
  ['control: 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]]]],
 [['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]]],
  ['regression: scenario 9',
   [150,
    [[True, 10],
     [True, 70],
     [True, 50],
     [False, 50],
     [False, 20],
     [False, 50],
     [True, 50],
     [True, 0],
     [True, 70],
     [False, 30],
     [True, 0],
     [False, 20],
     [False, 10]]],
   [[True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20],
    [True, True, 70],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 10]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: 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',
   [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 3',
   [60, [[False, 70], [True, 30], [True, 0], [True, 50], [True, 30], [True, 70], [True, 0]]],
   [[False, False, 60],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0]]]],
 [['regression: 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]]],
  ['regression: scenario 10',
   [150,
    [[False, 30],
     [True, 70],
     [False, 20],
     [False, 30],
     [False, 20],
     [False, 10],
     [False, 20],
     [False, 30],
     [True, 70],
     [True, 10],
     [False, 70],
     [False, 20]]],
   [[False, False, 150],
    [True, False, 0],
    [True, True, 0],
    [True, True, 30],
    [True, True, 50],
    [True, True, 60],
    [True, True, 80],
    [True, True, 110],
    [True, False, 0],
    [True, False, 0],
    [True, True, 0],
    [True, True, 20]]],
  ['regression: 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]]],
  ['regression: 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]]],
  ['control: 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 3',
   [0,
    [[False, 50],
     [False, 50],
     [False, 20],
     [False, 20],
     [True, 10],
     [True, 50],
     [True, 20],
     [False, 70],
     [False, 30],
     [False, 10],
     [True, 10],
     [True, 70],
     [True, 10],
     [False, 50]]],
   [[False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0],
    [False, False, 0],
    [False, False, 0],
    [True, False, 0],
    [True, False, 0],
    [True, False, 0],
    [False, False, 0]]]]]
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: 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
regression: 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
control: zero preset drop[[True, False, 0], [False, False, 0], [False, False, 0]][[True, False, 0], [False, False, 0], [False, False, 0]]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
regression: 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
regression: scenario 4[[False, False, 100], [False, False, 100], [True, False, 0], [True, True, 0], [True, True, 20], [True, True, 70], [False, False, 100], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50]][[False, False, 100], [False, False, 100], [True, False, 0], [True, True, 0], [True, True, 20], [True, True, 70], [False, False, 100], [True, False, 0], [True, False, 0], [True, True, 0], [True, True, 50]]Passed

SHA-256 / 7c69038e71529eb2a5da00f5d498b33a3371ee4841a188c3001f5f3c5ff4393e

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 2026-09-29T14:51:40.261841+00:00.

Case digest / da712716c6c4cf61694bdd50593df48f888327d06ba5a52051fd89c12bd08f6f