FA-92156 / PLC ladder logic scan cycles / Open access

New step inherits the previous step's excess time · case 01

A step can transition earlier than its minimum because leftover time from the previous step is carried in.

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

ROOT CAUSE

On transition the step time is reduced by the old minimum instead of reset.

VERIFIED REPAIR

Reset step time to 0 on every transition.

Unsuccessful approach: Seeding the new step with the current scan interval still credits time before activation.

Case contract

Cyclic step sequence with one active step. steps is a list of [min_time_ms, transition_tag]. Each scan [dt, inputs] first adds dt to the step time unless the step became active on the previous scan, then fires the transition if step time >= min_time and the transition tag is true. At most one transition fires per scan; after the last step the sequence returns to step 0; the new step time is 0. Step 0 is active before the first scan as if just entered. Return [active_step, step_time, entered_this_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(steps, scans):
    active = 0
    elapsed = 0
    entered = True
    out = []
    for dt, inputs in scans:
        if not entered:
            elapsed += dt
        entered = False
        min_ms, cond = steps[active]
        if elapsed >= min_ms and inputs.get(cond, False):
            active = (active + 1) % len(steps)
            elapsed -= min_ms
            entered = True
        out.append([active, elapsed, entered])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: scenario 1',
   [[[0, 'T2'], [100, 'T3'], [100, 'T2'], [100, 'T2']],
    [[25, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 50, False],
    [1, 90, False],
    [1, 110, False],
    [2, 0, True],
    [2, 0, False],
    [2, 50, False]]],
  ['regression: scenario 2',
   [[[20, 'T3'], [20, 'T3'], [20, 'T1']],
    [[50, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 40, False],
    [1, 0, True],
    [1, 0, False],
    [1, 40, False],
    [1, 80, False],
    [1, 105, False]]],
  ['regression: scenario 3',
   [[[0, 'T2'], [100, 'T3'], [100, 'T2']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}]]],
   [[1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [1, 20, False],
    [1, 40, False],
    [1, 80, False],
    [2, 0, True]]],
  ['regression: scenario 4',
   [[[0, 'T2'], [0, 'T3'], [0, 'T3'], [0, 'T2']],
    [[20, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [2, 0, True],
    [3, 0, True],
    [0, 0, True],
    [0, 0, False],
    [1, 0, True],
    [2, 0, True]]]],
 [['regression: scenario 1',
   [[[100, 'T3'], [0, 'T1']],
    [[50, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 65, False],
    [0, 75, False],
    [1, 0, True],
    [0, 0, True],
    [0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [0, 75, False]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 2',
   [[[100, 'T2'], [0, 'T1'], [50, 'T2'], [20, 'T2']],
    [[50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 20, False],
    [0, 40, False],
    [0, 65, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [2, 10, False],
    [2, 20, False],
    [2, 45, False],
    [2, 70, False],
    [2, 120, False],
    [3, 0, True],
    [3, 0, False]]],
  ['regression: scenario 3',
   [[[0, 'T2'], [0, 'T1'], [50, 'T1']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}]]],
   [[1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [0, 0, True],
    [0, 0, False],
    [0, 25, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [2, 25, False],
    [0, 0, True],
    [0, 0, False],
    [1, 0, True]]],
  ['regression: scenario 4',
   [[[0, 'T1'], [20, 'T2'], [20, 'T3']],
    [[40, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}]]],
   [[1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [2, 0, True],
    [2, 0, False],
    [2, 40, False],
    [0, 0, True],
    [0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False]]]],
 [['regression: scenario 2',
   [[[50, 'T3'], [0, 'T2'], [100, 'T1']],
    [[40, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 80, False],
    [1, 0, True],
    [1, 0, False],
    [1, 25, False],
    [1, 35, False],
    [1, 60, False],
    [2, 0, True],
    [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 1',
   [[[0, 'T3'], [20, 'T2'], [0, 'T2']],
    [[40, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 20, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [2, 0, True],
    [2, 0, False],
    [2, 50, False],
    [0, 0, True]]],
  ['regression: scenario 3',
   [[[50, 'T2'], [0, 'T3'], [100, 'T1'], [20, 'T3']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 25, False],
    [0, 35, False],
    [1, 0, True],
    [1, 0, False],
    [1, 40, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False],
    [2, 60, False],
    [3, 0, True],
    [3, 0, False]]],
  ['regression: scenario 4',
   [[[100, 'T1'], [50, 'T3'], [0, 'T1'], [0, 'T1']],
    [[10, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 50, False],
    [0, 70, False],
    [0, 90, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False]]]],
 [['regression: scenario 3',
   [[[100, 'T2'], [0, 'T2'], [0, 'T3']],
    [[50, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 10, False],
    [0, 30, False],
    [0, 70, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: scenario 1',
   [[[50, 'T1'], [50, 'T1'], [100, 'T3'], [20, 'T3']],
    [[20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [1, 0, True],
    [1, 0, False],
    [1, 50, False],
    [2, 0, True],
    [2, 0, False],
    [2, 25, False]]],
  ['regression: scenario 2',
   [[[0, 'T2'], [20, 'T3'], [0, 'T3'], [20, 'T1']],
    [[25, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}]]],
   [[0, 0, False], [0, 10, False], [0, 60, False], [1, 0, True], [1, 0, False], [2, 0, True]]],
  ['regression: scenario 4',
   [[[100, 'T2'], [20, 'T1'], [0, 'T3']],
    [[50, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 10, False],
    [0, 30, False],
    [0, 40, False],
    [0, 80, False],
    [0, 105, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [1, 70, False],
    [1, 120, False],
    [2, 0, True],
    [2, 0, False]]]],
 [['regression: scenario 4',
   [[[20, 'T1'], [50, 'T1'], [50, 'T3'], [0, 'T3']],
    [[25, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False],
    [2, 45, False],
    [2, 55, False],
    [3, 0, True],
    [3, 0, False],
    [0, 0, True]]],
  ['regression: scenario 1',
   [[[0, 'T2'], [100, 'T3'], [100, 'T1'], [20, 'T2']],
    [[40, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [0, 60, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [1, 40, False],
    [1, 80, False],
    [1, 90, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 2',
   [[[20, 'T1'], [20, 'T2'], [100, 'T3'], [0, 'T1']],
    [[50, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [1, 35, False],
    [1, 85, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False]]],
  ['regression: scenario 3',
   [[[20, 'T2'], [50, 'T2'], [0, 'T1']],
    [[50, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [2, 0, True],
    [0, 0, True],
    [0, 0, False],
    [0, 10, False],
    [0, 35, False],
    [1, 0, 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 fixture	Actual	Expected	Outcome
regression: late condition	`[[0, 0, False], [0, 15, False], [0, 30, False], [1, 25, True], [1, 25, False], [0, 20, True]]`	`[[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]`	Failed
regression: zero-time step chain	`[[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]`	`[[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]`	Passed
regression: two zero-time steps	`[[1, 0, True], [2, 0, True], [2, 0, False]]`	`[[1, 0, True], [2, 0, True], [2, 0, False]]`	Passed
regression: exact minimum time	`[[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]`	`[[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]`	Passed
regression: scenario 1	`[[0, 0, False], [1, 20, True], [1, 20, False], [1, 70, False], [2, 10, True], [2, 10, False], [2, 35, False], [2, 55, False], [3, 5, True]]`	`[[0, 0, False], [1, 0, True], [1, 0, False], [1, 50, False], [1, 90, False], [1, 110, False], [2, 0, True], [2, 0, False], [2, 50, False]]`	Failed
regression: scenario 2	`[[0, 0, False], [0, 40, False], [1, 30, True], [2, 10, True], [2, 10, False], [0, 30, True], [0, 30, False]]`	`[[0, 0, False], [0, 40, False], [1, 0, True], [1, 0, False], [1, 40, False], [1, 80, False], [1, 105, False]]`	Failed
regression: scenario 3	`[[1, 0, True], [1, 0, False], [1, 10, False], [1, 20, False], [1, 40, False], [1, 80, False], [2, 5, True]]`	`[[1, 0, True], [1, 0, False], [1, 10, False], [1, 20, False], [1, 40, False], [1, 80, False], [2, 0, True]]`	Failed
regression: scenario 4	`[[0, 0, False], [1, 20, True], [1, 20, False], [2, 40, True], [3, 40, True], [0, 40, True], [0, 40, False], [1, 80, True], [2, 80, True]]`	`[[0, 0, False], [1, 0, True], [1, 0, False], [2, 0, True], [3, 0, True], [0, 0, True], [0, 0, False], [1, 0, True], [2, 0, True]]`	Failed

SHA-256 / 32e13651cdcaee087cb22700d650dbc14581f93ed4a9738182d6ecf8726dd8a1

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(steps, scans):
    active = 0
    elapsed = 0
    entered = True
    out = []
    for dt, inputs in scans:
        if not entered:
            elapsed += dt
        entered = False
        min_ms, cond = steps[active]
        if elapsed >= min_ms and inputs.get(cond, False):
            active = (active + 1) % len(steps)
            elapsed = dt
            entered = True
        out.append([active, elapsed, entered])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: scenario 1',
   [[[0, 'T2'], [100, 'T3'], [100, 'T2'], [100, 'T2']],
    [[25, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 50, False],
    [1, 90, False],
    [1, 110, False],
    [2, 0, True],
    [2, 0, False],
    [2, 50, False]]],
  ['regression: scenario 2',
   [[[20, 'T3'], [20, 'T3'], [20, 'T1']],
    [[50, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 40, False],
    [1, 0, True],
    [1, 0, False],
    [1, 40, False],
    [1, 80, False],
    [1, 105, False]]],
  ['regression: scenario 3',
   [[[0, 'T2'], [100, 'T3'], [100, 'T2']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}]]],
   [[1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [1, 20, False],
    [1, 40, False],
    [1, 80, False],
    [2, 0, True]]],
  ['regression: scenario 4',
   [[[0, 'T2'], [0, 'T3'], [0, 'T3'], [0, 'T2']],
    [[20, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [2, 0, True],
    [3, 0, True],
    [0, 0, True],
    [0, 0, False],
    [1, 0, True],
    [2, 0, True]]]],
 [['regression: scenario 1',
   [[[100, 'T3'], [0, 'T1']],
    [[50, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 65, False],
    [0, 75, False],
    [1, 0, True],
    [0, 0, True],
    [0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [0, 75, False]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 2',
   [[[100, 'T2'], [0, 'T1'], [50, 'T2'], [20, 'T2']],
    [[50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 20, False],
    [0, 40, False],
    [0, 65, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [2, 10, False],
    [2, 20, False],
    [2, 45, False],
    [2, 70, False],
    [2, 120, False],
    [3, 0, True],
    [3, 0, False]]],
  ['regression: scenario 3',
   [[[0, 'T2'], [0, 'T1'], [50, 'T1']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}]]],
   [[1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [0, 0, True],
    [0, 0, False],
    [0, 25, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [2, 25, False],
    [0, 0, True],
    [0, 0, False],
    [1, 0, True]]],
  ['regression: scenario 4',
   [[[0, 'T1'], [20, 'T2'], [20, 'T3']],
    [[40, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}]]],
   [[1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [2, 0, True],
    [2, 0, False],
    [2, 40, False],
    [0, 0, True],
    [0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False]]]],
 [['regression: scenario 2',
   [[[50, 'T3'], [0, 'T2'], [100, 'T1']],
    [[40, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 80, False],
    [1, 0, True],
    [1, 0, False],
    [1, 25, False],
    [1, 35, False],
    [1, 60, False],
    [2, 0, True],
    [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 1',
   [[[0, 'T3'], [20, 'T2'], [0, 'T2']],
    [[40, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 20, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [2, 0, True],
    [2, 0, False],
    [2, 50, False],
    [0, 0, True]]],
  ['regression: scenario 3',
   [[[50, 'T2'], [0, 'T3'], [100, 'T1'], [20, 'T3']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 25, False],
    [0, 35, False],
    [1, 0, True],
    [1, 0, False],
    [1, 40, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False],
    [2, 60, False],
    [3, 0, True],
    [3, 0, False]]],
  ['regression: scenario 4',
   [[[100, 'T1'], [50, 'T3'], [0, 'T1'], [0, 'T1']],
    [[10, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 50, False],
    [0, 70, False],
    [0, 90, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False]]]],
 [['regression: scenario 3',
   [[[100, 'T2'], [0, 'T2'], [0, 'T3']],
    [[50, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 10, False],
    [0, 30, False],
    [0, 70, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: scenario 1',
   [[[50, 'T1'], [50, 'T1'], [100, 'T3'], [20, 'T3']],
    [[20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [1, 0, True],
    [1, 0, False],
    [1, 50, False],
    [2, 0, True],
    [2, 0, False],
    [2, 25, False]]],
  ['regression: scenario 2',
   [[[0, 'T2'], [20, 'T3'], [0, 'T3'], [20, 'T1']],
    [[25, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}]]],
   [[0, 0, False], [0, 10, False], [0, 60, False], [1, 0, True], [1, 0, False], [2, 0, True]]],
  ['regression: scenario 4',
   [[[100, 'T2'], [20, 'T1'], [0, 'T3']],
    [[50, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 10, False],
    [0, 30, False],
    [0, 40, False],
    [0, 80, False],
    [0, 105, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [1, 70, False],
    [1, 120, False],
    [2, 0, True],
    [2, 0, False]]]],
 [['regression: scenario 4',
   [[[20, 'T1'], [50, 'T1'], [50, 'T3'], [0, 'T3']],
    [[25, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False],
    [2, 45, False],
    [2, 55, False],
    [3, 0, True],
    [3, 0, False],
    [0, 0, True]]],
  ['regression: scenario 1',
   [[[0, 'T2'], [100, 'T3'], [100, 'T1'], [20, 'T2']],
    [[40, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [0, 60, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [1, 40, False],
    [1, 80, False],
    [1, 90, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 2',
   [[[20, 'T1'], [20, 'T2'], [100, 'T3'], [0, 'T1']],
    [[50, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [1, 35, False],
    [1, 85, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False]]],
  ['regression: scenario 3',
   [[[20, 'T2'], [50, 'T2'], [0, 'T1']],
    [[50, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [2, 0, True],
    [0, 0, True],
    [0, 0, False],
    [0, 10, False],
    [0, 35, False],
    [1, 0, 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 fixture	Actual	Expected	Outcome
regression: late condition	`[[0, 0, False], [0, 15, False], [0, 30, False], [1, 15, True], [1, 15, False], [0, 15, True]]`	`[[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]`	Failed
regression: zero-time step chain	`[[0, 0, False], [0, 10, False], [1, 10, True], [2, 15, True], [2, 15, False], [0, 15, True], [0, 15, False]]`	`[[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]`	Failed
regression: two zero-time steps	`[[1, 10, True], [2, 10, True], [2, 10, False]]`	`[[1, 0, True], [2, 0, True], [2, 0, False]]`	Failed
regression: exact minimum time	`[[0, 0, False], [0, 10, False], [0, 20, False], [1, 10, True], [0, 10, True], [0, 10, False]]`	`[[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]`	Failed
regression: scenario 1	`[[0, 0, False], [1, 20, True], [1, 20, False], [1, 70, False], [2, 40, True], [2, 40, False], [2, 65, False], [2, 85, False], [3, 50, True]]`	`[[0, 0, False], [1, 0, True], [1, 0, False], [1, 50, False], [1, 90, False], [1, 110, False], [2, 0, True], [2, 0, False], [2, 50, False]]`	Failed
regression: scenario 2	`[[0, 0, False], [0, 40, False], [1, 10, True], [1, 10, False], [1, 50, False], [1, 90, False], [1, 115, False]]`	`[[0, 0, False], [0, 40, False], [1, 0, True], [1, 0, False], [1, 40, False], [1, 80, False], [1, 105, False]]`	Failed
regression: scenario 3	`[[1, 25, True], [1, 25, False], [1, 35, False], [1, 45, False], [1, 65, False], [1, 105, False], [2, 25, True]]`	`[[1, 0, True], [1, 0, False], [1, 10, False], [1, 20, False], [1, 40, False], [1, 80, False], [2, 0, True]]`	Failed
regression: scenario 4	`[[0, 0, False], [1, 20, True], [1, 20, False], [2, 20, True], [3, 25, True], [0, 50, True], [0, 50, False], [1, 40, True], [2, 40, True]]`	`[[0, 0, False], [1, 0, True], [1, 0, False], [2, 0, True], [3, 0, True], [0, 0, True], [0, 0, False], [1, 0, True], [2, 0, True]]`	Failed

SHA-256 / 21c70225c8efb2a9624c432da01c44400516e62352ad04cadbb0641dc00f52fa

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(steps, scans):
    active = 0
    elapsed = 0
    entered = True
    out = []
    for dt, inputs in scans:
        if not entered:
            elapsed += dt
        entered = False
        min_ms, cond = steps[active]
        if elapsed >= min_ms and inputs.get(cond, False):
            active = (active + 1) % len(steps)
            elapsed = 0
            entered = True
        out.append([active, elapsed, entered])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: scenario 1',
   [[[0, 'T2'], [100, 'T3'], [100, 'T2'], [100, 'T2']],
    [[25, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 50, False],
    [1, 90, False],
    [1, 110, False],
    [2, 0, True],
    [2, 0, False],
    [2, 50, False]]],
  ['regression: scenario 2',
   [[[20, 'T3'], [20, 'T3'], [20, 'T1']],
    [[50, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 40, False],
    [1, 0, True],
    [1, 0, False],
    [1, 40, False],
    [1, 80, False],
    [1, 105, False]]],
  ['regression: scenario 3',
   [[[0, 'T2'], [100, 'T3'], [100, 'T2']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}]]],
   [[1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [1, 20, False],
    [1, 40, False],
    [1, 80, False],
    [2, 0, True]]],
  ['regression: scenario 4',
   [[[0, 'T2'], [0, 'T3'], [0, 'T3'], [0, 'T2']],
    [[20, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [2, 0, True],
    [3, 0, True],
    [0, 0, True],
    [0, 0, False],
    [1, 0, True],
    [2, 0, True]]]],
 [['regression: scenario 1',
   [[[100, 'T3'], [0, 'T1']],
    [[50, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 65, False],
    [0, 75, False],
    [1, 0, True],
    [0, 0, True],
    [0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [0, 75, False]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 2',
   [[[100, 'T2'], [0, 'T1'], [50, 'T2'], [20, 'T2']],
    [[50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 20, False],
    [0, 40, False],
    [0, 65, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [2, 10, False],
    [2, 20, False],
    [2, 45, False],
    [2, 70, False],
    [2, 120, False],
    [3, 0, True],
    [3, 0, False]]],
  ['regression: scenario 3',
   [[[0, 'T2'], [0, 'T1'], [50, 'T1']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}]]],
   [[1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [0, 0, True],
    [0, 0, False],
    [0, 25, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False],
    [2, 25, False],
    [0, 0, True],
    [0, 0, False],
    [1, 0, True]]],
  ['regression: scenario 4',
   [[[0, 'T1'], [20, 'T2'], [20, 'T3']],
    [[40, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}]]],
   [[1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [2, 0, True],
    [2, 0, False],
    [2, 40, False],
    [0, 0, True],
    [0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False]]]],
 [['regression: scenario 2',
   [[[50, 'T3'], [0, 'T2'], [100, 'T1']],
    [[40, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 80, False],
    [1, 0, True],
    [1, 0, False],
    [1, 25, False],
    [1, 35, False],
    [1, 60, False],
    [2, 0, True],
    [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 1',
   [[[0, 'T3'], [20, 'T2'], [0, 'T2']],
    [[40, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': False, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 20, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [2, 0, True],
    [2, 0, False],
    [2, 50, False],
    [0, 0, True]]],
  ['regression: scenario 3',
   [[[50, 'T2'], [0, 'T3'], [100, 'T1'], [20, 'T3']],
    [[25, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 25, False],
    [0, 35, False],
    [1, 0, True],
    [1, 0, False],
    [1, 40, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False],
    [2, 60, False],
    [3, 0, True],
    [3, 0, False]]],
  ['regression: scenario 4',
   [[[100, 'T1'], [50, 'T3'], [0, 'T1'], [0, 'T1']],
    [[10, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [0, 50, False],
    [0, 70, False],
    [0, 90, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False]]]],
 [['regression: scenario 3',
   [[[100, 'T2'], [0, 'T2'], [0, 'T3']],
    [[50, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [20, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 10, False],
    [0, 30, False],
    [0, 70, False],
    [1, 0, True],
    [2, 0, True],
    [2, 0, False]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: scenario 1',
   [[[50, 'T1'], [50, 'T1'], [100, 'T3'], [20, 'T3']],
    [[20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [1, 0, True],
    [1, 0, False],
    [1, 50, False],
    [2, 0, True],
    [2, 0, False],
    [2, 25, False]]],
  ['regression: scenario 2',
   [[[0, 'T2'], [20, 'T3'], [0, 'T3'], [20, 'T1']],
    [[25, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': True}]]],
   [[0, 0, False], [0, 10, False], [0, 60, False], [1, 0, True], [1, 0, False], [2, 0, True]]],
  ['regression: scenario 4',
   [[[100, 'T2'], [20, 'T1'], [0, 'T3']],
    [[50, {'T1': False, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': False, 'T2': False, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [0, 10, False],
    [0, 30, False],
    [0, 40, False],
    [0, 80, False],
    [0, 105, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [1, 70, False],
    [1, 120, False],
    [2, 0, True],
    [2, 0, False]]]],
 [['regression: scenario 4',
   [[[20, 'T1'], [50, 'T1'], [50, 'T3'], [0, 'T3']],
    [[25, {'T1': True, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': True}],
     [50, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': True, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False],
    [2, 45, False],
    [2, 55, False],
    [3, 0, True],
    [3, 0, False],
    [0, 0, True]]],
  ['regression: scenario 1',
   [[[0, 'T2'], [100, 'T3'], [100, 'T1'], [20, 'T2']],
    [[40, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': True, 'T3': True}],
     [20, {'T1': True, 'T2': False, 'T3': False}],
     [40, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': False, 'T2': False, 'T3': True}]]],
   [[0, 0, False],
    [0, 40, False],
    [0, 50, False],
    [0, 60, False],
    [1, 0, True],
    [1, 0, False],
    [1, 20, False],
    [1, 40, False],
    [1, 80, False],
    [1, 90, False]]],
  ['regression: zero-time step chain',
   [[[20, 'A'], [0, 'B'], [30, 'C']],
    [[10, {'A': True}],
     [10, {'A': True}],
     [10, {'A': True, 'B': True}],
     [15, {'B': True}],
     [15, {'C': True}],
     [15, {'C': True}],
     [15, {'C': True}]]],
   [[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]],
  ['regression: two zero-time steps',
   [[[0, 'A'], [0, 'A'], [0, 'A'], [50, 'B']], [[10, {'A': True}], [10, {'A': True}], [10, {}]]],
   [[1, 0, True], [2, 0, True], [2, 0, False]]],
  ['regression: exact minimum time',
   [[[30, 'X'], [10, 'Y']],
    [[10, {}], [10, {}], [10, {}], [10, {'X': True}], [10, {'Y': True}], [10, {'Y': True}]]],
   [[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]],
  ['regression: late condition',
   [[[20, 'X'], [20, 'Y']], [[15, {}], [15, {}], [15, {}], [15, {'X': True}], [15, {}], [15, {'Y': True}]]],
   [[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]],
  ['regression: scenario 2',
   [[[20, 'T1'], [20, 'T2'], [100, 'T3'], [0, 'T1']],
    [[50, {'T1': False, 'T2': True, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [20, {'T1': False, 'T2': False, 'T3': False}],
     [10, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': False, 'T3': True}],
     [40, {'T1': True, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': False, 'T3': False}],
     [20, {'T1': True, 'T2': False, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [1, 10, False],
    [1, 35, False],
    [1, 85, False],
    [2, 0, True],
    [2, 0, False],
    [2, 20, False]]],
  ['regression: scenario 3',
   [[[20, 'T2'], [50, 'T2'], [0, 'T1']],
    [[50, {'T1': False, 'T2': True, 'T3': False}],
     [25, {'T1': True, 'T2': True, 'T3': True}],
     [25, {'T1': False, 'T2': False, 'T3': False}],
     [50, {'T1': False, 'T2': True, 'T3': False}],
     [40, {'T1': True, 'T2': False, 'T3': False}],
     [50, {'T1': True, 'T2': True, 'T3': True}],
     [10, {'T1': False, 'T2': False, 'T3': True}],
     [25, {'T1': True, 'T2': False, 'T3': True}],
     [25, {'T1': False, 'T2': True, 'T3': False}]]],
   [[0, 0, False],
    [1, 0, True],
    [1, 0, False],
    [2, 0, True],
    [0, 0, True],
    [0, 0, False],
    [0, 10, False],
    [0, 35, False],
    [1, 0, 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 fixture	Actual	Expected	Outcome
regression: late condition	`[[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]`	`[[0, 0, False], [0, 15, False], [0, 30, False], [1, 0, True], [1, 0, False], [1, 15, False]]`	Passed
regression: zero-time step chain	`[[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]`	`[[0, 0, False], [0, 10, False], [1, 0, True], [2, 0, True], [2, 0, False], [2, 15, False], [0, 0, True]]`	Passed
regression: two zero-time steps	`[[1, 0, True], [2, 0, True], [2, 0, False]]`	`[[1, 0, True], [2, 0, True], [2, 0, False]]`	Passed
regression: exact minimum time	`[[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]`	`[[0, 0, False], [0, 10, False], [0, 20, False], [1, 0, True], [1, 0, False], [0, 0, True]]`	Passed
regression: scenario 1	`[[0, 0, False], [1, 0, True], [1, 0, False], [1, 50, False], [1, 90, False], [1, 110, False], [2, 0, True], [2, 0, False], [2, 50, False]]`	`[[0, 0, False], [1, 0, True], [1, 0, False], [1, 50, False], [1, 90, False], [1, 110, False], [2, 0, True], [2, 0, False], [2, 50, False]]`	Passed
regression: scenario 2	`[[0, 0, False], [0, 40, False], [1, 0, True], [1, 0, False], [1, 40, False], [1, 80, False], [1, 105, False]]`	`[[0, 0, False], [0, 40, False], [1, 0, True], [1, 0, False], [1, 40, False], [1, 80, False], [1, 105, False]]`	Passed
regression: scenario 3	`[[1, 0, True], [1, 0, False], [1, 10, False], [1, 20, False], [1, 40, False], [1, 80, False], [2, 0, True]]`	`[[1, 0, True], [1, 0, False], [1, 10, False], [1, 20, False], [1, 40, False], [1, 80, False], [2, 0, True]]`	Passed
regression: scenario 4	`[[0, 0, False], [1, 0, True], [1, 0, False], [2, 0, True], [3, 0, True], [0, 0, True], [0, 0, False], [1, 0, True], [2, 0, True]]`	`[[0, 0, False], [1, 0, True], [1, 0, False], [2, 0, True], [3, 0, True], [0, 0, True], [0, 0, False], [1, 0, True], [2, 0, True]]`	Passed

SHA-256 / 86a9df6f91a484f3f6869b1863e16dd0245f2c5e4022360ce1de734dec5e5a17

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 2026-09-29T14:51:43.037177+00:00.

Case digest / bd061ade7db650392333b310b90304d4dbebe32fdab301915ff2334a2573bbde