FAILURE MAP
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FA-92201 / PLC ladder logic scan cycles / Open access

A new alarm occurrence inherits the previous acknowledgement · case 01

An alarm that returns after being acknowledged is shown as already acknowledged.

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

ROOT CAUSE

Activation does not clear the acknowledged flag.

VERIFIED REPAIR

Clear the acknowledged flag on every new activation.

Unsuccessful approach: Clearing acknowledgement only for latched alarms still hides returning non-latched alarms.

Case contract

Digital alarm instruction evaluated per scan; scans is a list of [condition, ack, reset], min_scans >= 1. The alarm activates when the condition has been true for min_scans consecutive scans; activation clears the acknowledged flag. A non-latched alarm clears when the condition goes false; a latched alarm clears only on a reset while the condition is false. ack sets acknowledged. Return [in_alarm, acknowledged] 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(min_scans, latched, scans):
    in_alarm = False
    acked = True
    count = 0
    out = []
    for cond, ack, reset in scans:
        count = count + 1 if cond else 0
        if count >= min_scans and cond and not in_alarm:
            in_alarm = True
        elif in_alarm and not cond and (not latched or reset):
            in_alarm = False
        if ack and not acked:
            acked = True
        out.append([in_alarm, acked])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 1',
   [1,
    False,
    [[True, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False]]],
   [[True, False],
    [False, False],
    [True, False],
    [False, False],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 2',
   [1,
    True,
    [[False, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, True],
     [False, False, False],
     [False, True, False],
     [True, False, False],
     [False, False, False]]],
   [[False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, True],
    [True, False],
    [True, False]]],
  ['regression: scenario 3',
   [3,
    False,
    [[True, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False],
     [False, False, True],
     [True, False, False],
     [True, True, False],
     [False, True, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False]]]],
 [['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 1',
   [1,
    False,
    [[False, False, False],
     [False, False, True],
     [False, False, False],
     [True, True, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 2',
   [3,
    False,
    [[False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [False, False, True],
     [False, True, False],
     [True, False, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 3',
   [2,
    False,
    [[True, False, False],
     [True, False, True],
     [False, True, True],
     [False, False, False],
     [False, False, True],
     [True, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False]]],
   [[False, True],
    [True, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True]]]],
 [['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: scenario 1',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 2',
   [2,
    True,
    [[False, True, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, True],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['regression: scenario 3',
   [3,
    True,
    [[True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, True],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [False, True, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]]],
 [['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: scenario 9',
   [2,
    False,
    [[True, True, False],
     [False, False, False],
     [True, False, False],
     [False, True, True],
     [True, False, False],
     [True, True, False],
     [False, False, False],
     [True, True, False],
     [False, False, False],
     [False, True, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['control: scenario 1',
   [2,
    True,
    [[False, True, False],
     [True, False, False],
     [False, False, False],
     [False, False, True],
     [False, False, True],
     [True, False, True],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['control: scenario 2',
   [2,
    False,
    [[False, True, False],
     [True, False, False],
     [True, True, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, True],
     [False, False, False],
     [True, False, True],
     [True, True, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True]]]],
 [['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 4',
   [3,
    False,
    [[True, False, False],
     [True, False, True],
     [True, False, True],
     [True, False, True],
     [False, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False],
     [False, False, False],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: scenario 1',
   [2,
    False,
    [[False, False, False],
     [True, True, False],
     [True, True, False],
     [False, False, True],
     [False, False, True],
     [True, True, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, True]]],
   [[False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [False, False],
    [False, False],
    [True, False]]],
  ['control: scenario 2',
   [2,
    False,
    [[False, True, False],
     [True, True, True],
     [False, False, False],
     [False, True, True],
     [True, False, False],
     [False, False, False],
     [True, False, True],
     [False, False, False],
     [True, False, False],
     [False, True, False],
     [False, True, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True]]]]]
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: latched with ack and reset[[False, True], [True, True], [True, True], [True, True], [False, True], [False, True]][[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]Failed
regression: chattering condition[[False, True], [False, True], [False, True], [False, True], [False, True], [True, True]][[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]Failed
regression: realarm after ack[[True, True], [True, True], [False, True], [True, True]][[True, False], [True, True], [False, True], [True, False]]Failed
regression: reset while condition true[[True, True], [True, True], [True, True]][[True, False], [True, False], [True, False]]Failed
regression: ack on latched alarm[[True, True], [True, True], [True, True], [False, True]][[True, False], [True, True], [True, True], [False, True]]Failed
regression: scenario 1[[True, True], [False, True], [True, True], [False, True], [True, True], [True, True], [True, True], [False, True], [False, True], [True, True]][[True, False], [False, False], [True, False], [False, False], [True, True], [True, True], [True, True], [False, True], [False, True], [True, False]]Failed
regression: scenario 2[[False, True], [True, True], [True, True], [True, True], [True, True], [True, True], [True, True], [False, True], [False, True], [False, True], [True, True], [True, True]][[False, True], [True, False], [True, False], [True, False], [True, False], [True, False], [True, False], [False, False], [False, False], [False, True], [True, False], [True, False]]Failed
regression: scenario 3[[False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [True, True]][[False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]Failed

SHA-256 / 76401ba111dfb295a539f713295c53318e5c2699521e0cbdf8d5400dccdf43c7

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(min_scans, latched, scans):
    in_alarm = False
    acked = True
    count = 0
    out = []
    for cond, ack, reset in scans:
        count = count + 1 if cond else 0
        if count >= min_scans and cond and not in_alarm:
            in_alarm = True
            acked = acked and not latched
        elif in_alarm and not cond and (not latched or reset):
            in_alarm = False
        if ack and not acked:
            acked = True
        out.append([in_alarm, acked])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 1',
   [1,
    False,
    [[True, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False]]],
   [[True, False],
    [False, False],
    [True, False],
    [False, False],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 2',
   [1,
    True,
    [[False, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, True],
     [False, False, False],
     [False, True, False],
     [True, False, False],
     [False, False, False]]],
   [[False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, True],
    [True, False],
    [True, False]]],
  ['regression: scenario 3',
   [3,
    False,
    [[True, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False],
     [False, False, True],
     [True, False, False],
     [True, True, False],
     [False, True, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False]]]],
 [['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 1',
   [1,
    False,
    [[False, False, False],
     [False, False, True],
     [False, False, False],
     [True, True, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 2',
   [3,
    False,
    [[False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [False, False, True],
     [False, True, False],
     [True, False, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 3',
   [2,
    False,
    [[True, False, False],
     [True, False, True],
     [False, True, True],
     [False, False, False],
     [False, False, True],
     [True, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False]]],
   [[False, True],
    [True, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True]]]],
 [['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: scenario 1',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 2',
   [2,
    True,
    [[False, True, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, True],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['regression: scenario 3',
   [3,
    True,
    [[True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, True],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [False, True, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]]],
 [['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: scenario 9',
   [2,
    False,
    [[True, True, False],
     [False, False, False],
     [True, False, False],
     [False, True, True],
     [True, False, False],
     [True, True, False],
     [False, False, False],
     [True, True, False],
     [False, False, False],
     [False, True, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['control: scenario 1',
   [2,
    True,
    [[False, True, False],
     [True, False, False],
     [False, False, False],
     [False, False, True],
     [False, False, True],
     [True, False, True],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['control: scenario 2',
   [2,
    False,
    [[False, True, False],
     [True, False, False],
     [True, True, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, True],
     [False, False, False],
     [True, False, True],
     [True, True, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True]]]],
 [['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 4',
   [3,
    False,
    [[True, False, False],
     [True, False, True],
     [True, False, True],
     [True, False, True],
     [False, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False],
     [False, False, False],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: scenario 1',
   [2,
    False,
    [[False, False, False],
     [True, True, False],
     [True, True, False],
     [False, False, True],
     [False, False, True],
     [True, True, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, True]]],
   [[False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [False, False],
    [False, False],
    [True, False]]],
  ['control: scenario 2',
   [2,
    False,
    [[False, True, False],
     [True, True, True],
     [False, False, False],
     [False, True, True],
     [True, False, False],
     [False, False, False],
     [True, False, True],
     [False, False, False],
     [True, False, False],
     [False, True, False],
     [False, True, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True]]]]]
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: latched with ack and reset[[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]][[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]Passed
regression: chattering condition[[False, True], [False, True], [False, True], [False, True], [False, True], [True, True]][[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]Failed
regression: realarm after ack[[True, True], [True, True], [False, True], [True, True]][[True, False], [True, True], [False, True], [True, False]]Failed
regression: reset while condition true[[True, True], [True, True], [True, True]][[True, False], [True, False], [True, False]]Failed
regression: ack on latched alarm[[True, False], [True, True], [True, True], [False, True]][[True, False], [True, True], [True, True], [False, True]]Passed
regression: scenario 1[[True, True], [False, True], [True, True], [False, True], [True, True], [True, True], [True, True], [False, True], [False, True], [True, True]][[True, False], [False, False], [True, False], [False, False], [True, True], [True, True], [True, True], [False, True], [False, True], [True, False]]Failed
regression: scenario 2[[False, True], [True, False], [True, False], [True, False], [True, False], [True, False], [True, False], [False, False], [False, False], [False, True], [True, False], [True, False]][[False, True], [True, False], [True, False], [True, False], [True, False], [True, False], [True, False], [False, False], [False, False], [False, True], [True, False], [True, False]]Passed
regression: scenario 3[[False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [True, True]][[False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]Failed

SHA-256 / 93210d81bfca0e92556f9fdec952af4dfbcc368605d6572c21ded435791763b5

3 / The verified repair

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

N = 1
observations = []
def solve(min_scans, latched, scans):
    in_alarm = False
    acked = True
    count = 0
    out = []
    for cond, ack, reset in scans:
        count = count + 1 if cond else 0
        if count >= min_scans and cond and not in_alarm:
            in_alarm = True
            acked = False
        elif in_alarm and not cond and (not latched or reset):
            in_alarm = False
        if ack and not acked:
            acked = True
        out.append([in_alarm, acked])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 1',
   [1,
    False,
    [[True, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False]]],
   [[True, False],
    [False, False],
    [True, False],
    [False, False],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 2',
   [1,
    True,
    [[False, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, True],
     [False, False, False],
     [False, True, False],
     [True, False, False],
     [False, False, False]]],
   [[False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, True],
    [True, False],
    [True, False]]],
  ['regression: scenario 3',
   [3,
    False,
    [[True, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False],
     [False, False, True],
     [True, False, False],
     [True, True, False],
     [False, True, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False]]]],
 [['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 1',
   [1,
    False,
    [[False, False, False],
     [False, False, True],
     [False, False, False],
     [True, True, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 2',
   [3,
    False,
    [[False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [False, False, True],
     [False, True, False],
     [True, False, False],
     [False, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False]]],
  ['regression: scenario 3',
   [2,
    False,
    [[True, False, False],
     [True, False, True],
     [False, True, True],
     [False, False, False],
     [False, False, True],
     [True, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False]]],
   [[False, True],
    [True, False],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True]]]],
 [['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: scenario 1',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, False],
    [True, False],
    [False, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 2',
   [2,
    True,
    [[False, True, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, True],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['regression: scenario 3',
   [3,
    True,
    [[True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, True],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [False, True, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, False],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]]],
 [['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: scenario 9',
   [2,
    False,
    [[True, True, False],
     [False, False, False],
     [True, False, False],
     [False, True, True],
     [True, False, False],
     [True, True, False],
     [False, False, False],
     [True, True, False],
     [False, False, False],
     [False, True, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['control: scenario 1',
   [2,
    True,
    [[False, True, False],
     [True, False, False],
     [False, False, False],
     [False, False, True],
     [False, False, True],
     [True, False, True],
     [True, True, False],
     [True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True],
    [True, True]]],
  ['control: scenario 2',
   [2,
    False,
    [[False, True, False],
     [True, False, False],
     [True, True, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [False, False, False],
     [False, False, False],
     [True, False, False],
     [True, True, False],
     [True, False, True],
     [False, False, False],
     [True, False, True],
     [True, True, False],
     [True, False, False]]],
   [[False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True],
    [False, True],
    [False, True],
    [True, True],
    [True, True]]]],
 [['regression: ack on latched alarm',
   [1, True, [[True, False, False], [False, True, False], [False, False, False], [False, False, True]]],
   [[True, False], [True, True], [True, True], [False, True]]],
  ['regression: scenario 4',
   [3,
    False,
    [[True, False, False],
     [True, False, True],
     [True, False, True],
     [True, False, True],
     [False, False, False],
     [True, False, True],
     [False, False, False],
     [False, False, False],
     [False, False, False],
     [False, False, True]]],
   [[False, True],
    [False, True],
    [True, False],
    [True, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False],
    [False, False]]],
  ['regression: latched with ack and reset',
   [2,
    True,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [False, True, False],
     [False, False, True],
     [True, False, False]]],
   [[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]],
  ['regression: chattering condition',
   [3,
    False,
    [[True, False, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, False],
     [True, False, False]]],
   [[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]],
  ['regression: realarm after ack',
   [1, False, [[True, False, False], [True, True, False], [False, False, False], [True, False, False]]],
   [[True, False], [True, True], [False, True], [True, False]]],
  ['regression: reset while condition true',
   [1, False, [[True, False, False], [True, False, True], [True, False, False]]],
   [[True, False], [True, False], [True, False]]],
  ['regression: scenario 1',
   [2,
    False,
    [[False, False, False],
     [True, True, False],
     [True, True, False],
     [False, False, True],
     [False, False, True],
     [True, True, False],
     [True, False, False],
     [False, False, False],
     [True, False, False],
     [True, False, True]]],
   [[False, True],
    [False, True],
    [True, True],
    [False, True],
    [False, True],
    [False, True],
    [True, False],
    [False, False],
    [False, False],
    [True, False]]],
  ['control: scenario 2',
   [2,
    False,
    [[False, True, False],
     [True, True, True],
     [False, False, False],
     [False, True, True],
     [True, False, False],
     [False, False, False],
     [True, False, True],
     [False, False, False],
     [True, False, False],
     [False, True, False],
     [False, True, False]]],
   [[False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True],
    [False, True]]]]]
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: latched with ack and reset[[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]][[False, True], [True, False], [True, False], [True, True], [False, True], [False, True]]Passed
regression: chattering condition[[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]][[False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]Passed
regression: realarm after ack[[True, False], [True, True], [False, True], [True, False]][[True, False], [True, True], [False, True], [True, False]]Passed
regression: reset while condition true[[True, False], [True, False], [True, False]][[True, False], [True, False], [True, False]]Passed
regression: ack on latched alarm[[True, False], [True, True], [True, True], [False, True]][[True, False], [True, True], [True, True], [False, True]]Passed
regression: scenario 1[[True, False], [False, False], [True, False], [False, False], [True, True], [True, True], [True, True], [False, True], [False, True], [True, False]][[True, False], [False, False], [True, False], [False, False], [True, True], [True, True], [True, True], [False, True], [False, True], [True, False]]Passed
regression: scenario 2[[False, True], [True, False], [True, False], [True, False], [True, False], [True, False], [True, False], [False, False], [False, False], [False, True], [True, False], [True, False]][[False, True], [True, False], [True, False], [True, False], [True, False], [True, False], [True, False], [False, False], [False, False], [False, True], [True, False], [True, False]]Passed
regression: scenario 3[[False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [True, False]][[False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [False, True], [True, False]]Passed

SHA-256 / 849274bfec38439e0492f0202ed14c9cb8a58a9b9921e3c2965ade8e6406ee9c

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 2026-09-29T14:51:43.597224+00:00.

Case digest / 43a556fae072ab1240c468701722daffba1363eb84e7a05e3f1d25e32cb2ad0e