FA-67791 / Elevator dispatch scheduling / Open access

Hall button registration and cancellation: terminal reversal service · case 01

A car reaching a terminal floor leaves the reversing call lit.

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

ROOT CAUSE

Terminal floors do not serve the opposite direction.

VERIFIED REPAIR

Serve both directions at terminal floors.

Unsuccessful approach: Handling only the top floor misses the reversal at the lobby.

Case contract

Hall buttons exist on floors 0..floors-1, except no up button at the top floor and no down button at the bottom floor; other presses are ignored. A registered call lights. A car arriving at a floor serves calls matching its direction; an idle car or a car arriving at a terminal floor (where it must reverse) serves both directions. Log lit/ignored and served:<dirs> (sorted), and list pending calls sorted.

Why this case matters

Lift group controllers make these decisions many times per minute; a wrong answer strands passengers, wastes trips or overrides a safety rule.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(x):
    top = x['floors'] - 1
    calls = set()
    out = []
    for kind, f, d in x['events']:
        if kind == 'press':
            if not (0 <= f <= top) or (f == top and d == 'up') or (f == 0 and d == 'down'):
                out.append('ignored')
                continue
            calls.add((f, d))
            out.append('lit')
        else:
            both = d == 'idle'
            served = sorted(c for c in calls if c[0] == f and (both or c[1] == d))
            for c in served:
                calls.discard(c)
            out.append('served:' + ','.join(c[1] for c in served))
    return {'log': out, 'pending': sorted([list(c) for c in calls])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: up button at the top floor', {'floors': 6, 'events': [['press', 5, 'up'], ['press', 5, 'down']]}, {'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}), ('boundary: down button at the lobby', {'floors': 6, 'events': [['press', 0, 'down'], ['press', 0, 'up']]}, {'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}), ('sampled regression 1', {'floors': 5, 'events': [['press', -1, 'down'], ['press', 4, 'down'], ['press', 4, 'down'], ['arrive', 3, 'idle'], ['press', 0, 'up'], ['press', 1, 'down'], ['press', 2, 'up'], ['arrive', 4, 'up']]}, {'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}), ('control 4', {'floors': 6, 'events': [['arrive', 2, 'up'], ['press', 1, 'up'], ['press', 5, 'down'], ['press', 1, 'down'], ['arrive', 4, 'up'], ['arrive', 3, 'up'], ['arrive', 0, 'idle'], ['arrive', 0, 'idle'], ['arrive', 5, 'down'], ['press', 0, 'down']]}, {'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}), ('control 7', {'floors': 5, 'events': [['arrive', 4, 'idle'], ['press', 3, 'down'], ['arrive', 2, 'down'], ['arrive', 3, 'idle'], ['arrive', 3, 'up'], ['press', 1, 'down']]}, {'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]})], [('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: idle car serves both lamps', {'floors': 6, 'events': [['press', 3, 'up'], ['press', 3, 'down'], ['arrive', 3, 'idle']]}, {'log': ['lit', 'lit', 'served:down,up'], 'pending': []}), ('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('boundary: floor above the shaft', {'floors': 6, 'events': [['press', 6, 'down'], ['press', -1, 'up']]}, {'log': ['ignored', 'ignored'], 'pending': []}), ('control 12', {'floors': 7, 'events': [['press', 5, 'up'], ['press', 6, 'down'], ['arrive', 2, 'idle'], ['arrive', 5, 'down'], ['press', 6, 'up']]}, {'log': ['lit', 'lit', 'served:', 'served:', 'ignored'], 'pending': [[5, 'up'], [6, 'down']]}), ('control 15', {'floors': 10, 'events': [['press', 9, 'up'], ['arrive', 5, 'down'], ['arrive', 9, 'up'], ['press', 0, 'down'], ['press', 10, 'down'], ['press', 2, 'down']]}, {'log': ['ignored', 'served:', 'served:', 'ignored', 'ignored', 'lit'], 'pending': [[2, 'down']]}), ('control 18', {'floors': 9, 'events': [['press', 5, 'down'], ['press', 1, 'down'], ['press', 7, 'down'], ['arrive', 0, 'up'], ['arrive', 3, 'up'], ['press', 7, 'up'], ['press', 5, 'up'], ['press', 8, 'up'], ['arrive', 8, 'up']]}, {'log': ['lit', 'lit', 'lit', 'served:', 'served:', 'lit', 'lit', 'ignored', 'served:'], 'pending': [[1, 'down'], [5, 'down'], [5, 'up'], [7, 'down'], [7, 'up']]})], [('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 77', {'floors': 6, 'events': [['press', 0, 'up'], ['press', -1, 'up'], ['arrive', 0, 'down'], ['arrive', 5, 'idle'], ['press', 3, 'up'], ['press', 5, 'up'], ['arrive', 5, 'up']]}, {'log': ['lit', 'ignored', 'served:up', 'served:', 'lit', 'ignored', 'served:'], 'pending': [[3, 'up']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: floor above the shaft', {'floors': 6, 'events': [['press', 6, 'down'], ['press', -1, 'up']]}, {'log': ['ignored', 'ignored'], 'pending': []}), ('control 23', {'floors': 10, 'events': [['press', 5, 'up'], ['press', 1, 'up'], ['arrive', 9, 'up'], ['arrive', 9, 'idle'], ['press', 9, 'up'], ['press', 9, 'up'], ['arrive', 1, 'down'], ['arrive', 9, 'up'], ['press', 4, 'up'], ['press', 4, 'down']]}, {'log': ['lit', 'lit', 'served:', 'served:', 'ignored', 'ignored', 'served:', 'served:', 'lit', 'lit'], 'pending': [[1, 'up'], [4, 'down'], [4, 'up'], [5, 'up']]}), ('control 29', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'idle'], ['press', 5, 'up'], ['press', 6, 'down'], ['press', 0, 'up'], ['arrive', 5, 'down']]}, {'log': ['lit', 'served:up', 'ignored', 'ignored', 'lit', 'served:'], 'pending': [[0, 'up']]}), ('control 32', {'floors': 5, 'events': [['press', -1, 'up'], ['arrive', 4, 'idle'], ['press', 2, 'up'], ['press', -1, 'up']]}, {'log': ['ignored', 'served:', 'lit', 'ignored'], 'pending': [[2, 'up']]})], [('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 60', {'floors': 8, 'events': [['press', 0, 'up'], ['arrive', 0, 'down'], ['arrive', 1, 'idle'], ['press', 7, 'down'], ['press', 4, 'down'], ['arrive', 5, 'idle'], ['arrive', 5, 'idle'], ['press', 7, 'up']]}, {'log': ['lit', 'served:up', 'served:', 'lit', 'lit', 'served:', 'served:', 'ignored'], 'pending': [[4, 'down'], [7, 'down']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: passing car in the other direction', {'floors': 6, 'events': [['press', 2, 'down'], ['arrive', 2, 'up']]}, {'log': ['lit', 'served:'], 'pending': [[2, 'down']]}), ('boundary: up button at the top floor', {'floors': 6, 'events': [['press', 5, 'up'], ['press', 5, 'down']]}, {'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}), ('control 34', {'floors': 5, 'events': [['arrive', 3, 'up'], ['arrive', 0, 'idle'], ['arrive', 3, 'idle'], ['arrive', 1, 'idle'], ['arrive', 0, 'down'], ['arrive', 2, 'down'], ['arrive', 1, 'down'], ['press', 1, 'down'], ['press', 4, 'up'], ['arrive', 3, 'down']]}, {'log': ['served:', 'served:', 'served:', 'served:', 'served:', 'served:', 'served:', 'lit', 'ignored', 'served:'], 'pending': [[1, 'down']]}), ('control 37', {'floors': 7, 'events': [['arrive', 4, 'up'], ['press', 1, 'up'], ['arrive', 2, 'down'], ['press', 4, 'down'], ['arrive', 0, 'idle'], ['press', 4, 'down']]}, {'log': ['served:', 'lit', 'served:', 'lit', 'served:', 'lit'], 'pending': [[1, 'up'], [4, 'down']]}), ('control 40', {'floors': 9, 'events': [['arrive', 1, 'idle'], ['press', 7, 'down'], ['arrive', 0, 'down'], ['press', -1, 'up']]}, {'log': ['served:', 'lit', 'served:', 'ignored'], 'pending': [[7, 'down']]})], [('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 39', {'floors': 7, 'events': [['press', 4, 'down'], ['press', 1, 'up'], ['press', 6, 'down'], ['arrive', 6, 'up'], ['arrive', 0, 'up'], ['press', 6, 'down'], ['arrive', 1, 'idle'], ['press', 2, 'down']]}, {'log': ['lit', 'lit', 'lit', 'served:down', 'served:', 'lit', 'served:up', 'lit'], 'pending': [[2, 'down'], [4, 'down'], [6, 'down']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: down button at the lobby', {'floors': 6, 'events': [['press', 0, 'down'], ['press', 0, 'up']]}, {'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}), ('control 45', {'floors': 5, 'events': [['arrive', 4, 'up'], ['arrive', 2, 'up'], ['press', -1, 'up'], ['press', 4, 'down'], ['press', 3, 'up'], ['press', 4, 'down'], ['arrive', 2, 'up']]}, {'log': ['served:', 'served:', 'ignored', 'lit', 'lit', 'lit', 'served:'], 'pending': [[3, 'up'], [4, 'down']]}), ('control 48', {'floors': 9, 'events': [['arrive', 8, 'idle'], ['press', 2, 'down'], ['press', 2, 'down'], ['press', 9, 'down'], ['press', -1, 'up'], ['arrive', 0, 'idle'], ['press', 8, 'down']]}, {'log': ['served:', 'lit', 'lit', 'ignored', 'ignored', 'served:', 'lit'], 'pending': [[2, 'down'], [8, 'down']]}), ('control 51', {'floors': 7, 'events': [['press', 7, 'down'], ['press', 4, 'down'], ['press', 6, 'down']]}, {'log': ['ignored', 'lit', 'lit'], 'pending': [[4, 'down'], [6, 'down']]})]]
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: up car at the top floor reverses	`{'log': ['lit', 'served:'], 'pending': [[5, 'down']]}`	`{'log': ['lit', 'served:down'], 'pending': []}`	Failed
regression: down car at the lobby reverses	`{'log': ['lit', 'served:'], 'pending': [[0, 'up']]}`	`{'log': ['lit', 'served:up'], 'pending': []}`	Failed
sampled regression 26	`{'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:', 'lit'], 'pending': [[0, 'up'], [3, 'up'], [4, 'down']]}`	`{'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}`	Failed
boundary: up button at the top floor	`{'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}`	`{'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}`	Passed
boundary: down button at the lobby	`{'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}`	`{'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}`	Passed
sampled regression 1	`{'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up'], [4, 'down']]}`	`{'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}`	Failed
control 4	`{'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}`	`{'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}`	Passed
control 7	`{'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]}`	`{'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]}`	Passed

SHA-256 / f7dade92c61f34e6fb2ef491383f83853855422f3459799661b6d19db5276d96

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(x):
    top = x['floors'] - 1
    calls = set()
    out = []
    for kind, f, d in x['events']:
        if kind == 'press':
            if not (0 <= f <= top) or (f == top and d == 'up') or (f == 0 and d == 'down'):
                out.append('ignored')
                continue
            calls.add((f, d))
            out.append('lit')
        else:
            both = d == 'idle' or f == top
            served = sorted(c for c in calls if c[0] == f and (both or c[1] == d))
            for c in served:
                calls.discard(c)
            out.append('served:' + ','.join(c[1] for c in served))
    return {'log': out, 'pending': sorted([list(c) for c in calls])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: up button at the top floor', {'floors': 6, 'events': [['press', 5, 'up'], ['press', 5, 'down']]}, {'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}), ('boundary: down button at the lobby', {'floors': 6, 'events': [['press', 0, 'down'], ['press', 0, 'up']]}, {'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}), ('sampled regression 1', {'floors': 5, 'events': [['press', -1, 'down'], ['press', 4, 'down'], ['press', 4, 'down'], ['arrive', 3, 'idle'], ['press', 0, 'up'], ['press', 1, 'down'], ['press', 2, 'up'], ['arrive', 4, 'up']]}, {'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}), ('control 4', {'floors': 6, 'events': [['arrive', 2, 'up'], ['press', 1, 'up'], ['press', 5, 'down'], ['press', 1, 'down'], ['arrive', 4, 'up'], ['arrive', 3, 'up'], ['arrive', 0, 'idle'], ['arrive', 0, 'idle'], ['arrive', 5, 'down'], ['press', 0, 'down']]}, {'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}), ('control 7', {'floors': 5, 'events': [['arrive', 4, 'idle'], ['press', 3, 'down'], ['arrive', 2, 'down'], ['arrive', 3, 'idle'], ['arrive', 3, 'up'], ['press', 1, 'down']]}, {'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]})], [('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: idle car serves both lamps', {'floors': 6, 'events': [['press', 3, 'up'], ['press', 3, 'down'], ['arrive', 3, 'idle']]}, {'log': ['lit', 'lit', 'served:down,up'], 'pending': []}), ('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('boundary: floor above the shaft', {'floors': 6, 'events': [['press', 6, 'down'], ['press', -1, 'up']]}, {'log': ['ignored', 'ignored'], 'pending': []}), ('control 12', {'floors': 7, 'events': [['press', 5, 'up'], ['press', 6, 'down'], ['arrive', 2, 'idle'], ['arrive', 5, 'down'], ['press', 6, 'up']]}, {'log': ['lit', 'lit', 'served:', 'served:', 'ignored'], 'pending': [[5, 'up'], [6, 'down']]}), ('control 15', {'floors': 10, 'events': [['press', 9, 'up'], ['arrive', 5, 'down'], ['arrive', 9, 'up'], ['press', 0, 'down'], ['press', 10, 'down'], ['press', 2, 'down']]}, {'log': ['ignored', 'served:', 'served:', 'ignored', 'ignored', 'lit'], 'pending': [[2, 'down']]}), ('control 18', {'floors': 9, 'events': [['press', 5, 'down'], ['press', 1, 'down'], ['press', 7, 'down'], ['arrive', 0, 'up'], ['arrive', 3, 'up'], ['press', 7, 'up'], ['press', 5, 'up'], ['press', 8, 'up'], ['arrive', 8, 'up']]}, {'log': ['lit', 'lit', 'lit', 'served:', 'served:', 'lit', 'lit', 'ignored', 'served:'], 'pending': [[1, 'down'], [5, 'down'], [5, 'up'], [7, 'down'], [7, 'up']]})], [('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 77', {'floors': 6, 'events': [['press', 0, 'up'], ['press', -1, 'up'], ['arrive', 0, 'down'], ['arrive', 5, 'idle'], ['press', 3, 'up'], ['press', 5, 'up'], ['arrive', 5, 'up']]}, {'log': ['lit', 'ignored', 'served:up', 'served:', 'lit', 'ignored', 'served:'], 'pending': [[3, 'up']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: floor above the shaft', {'floors': 6, 'events': [['press', 6, 'down'], ['press', -1, 'up']]}, {'log': ['ignored', 'ignored'], 'pending': []}), ('control 23', {'floors': 10, 'events': [['press', 5, 'up'], ['press', 1, 'up'], ['arrive', 9, 'up'], ['arrive', 9, 'idle'], ['press', 9, 'up'], ['press', 9, 'up'], ['arrive', 1, 'down'], ['arrive', 9, 'up'], ['press', 4, 'up'], ['press', 4, 'down']]}, {'log': ['lit', 'lit', 'served:', 'served:', 'ignored', 'ignored', 'served:', 'served:', 'lit', 'lit'], 'pending': [[1, 'up'], [4, 'down'], [4, 'up'], [5, 'up']]}), ('control 29', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'idle'], ['press', 5, 'up'], ['press', 6, 'down'], ['press', 0, 'up'], ['arrive', 5, 'down']]}, {'log': ['lit', 'served:up', 'ignored', 'ignored', 'lit', 'served:'], 'pending': [[0, 'up']]}), ('control 32', {'floors': 5, 'events': [['press', -1, 'up'], ['arrive', 4, 'idle'], ['press', 2, 'up'], ['press', -1, 'up']]}, {'log': ['ignored', 'served:', 'lit', 'ignored'], 'pending': [[2, 'up']]})], [('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 60', {'floors': 8, 'events': [['press', 0, 'up'], ['arrive', 0, 'down'], ['arrive', 1, 'idle'], ['press', 7, 'down'], ['press', 4, 'down'], ['arrive', 5, 'idle'], ['arrive', 5, 'idle'], ['press', 7, 'up']]}, {'log': ['lit', 'served:up', 'served:', 'lit', 'lit', 'served:', 'served:', 'ignored'], 'pending': [[4, 'down'], [7, 'down']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: passing car in the other direction', {'floors': 6, 'events': [['press', 2, 'down'], ['arrive', 2, 'up']]}, {'log': ['lit', 'served:'], 'pending': [[2, 'down']]}), ('boundary: up button at the top floor', {'floors': 6, 'events': [['press', 5, 'up'], ['press', 5, 'down']]}, {'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}), ('control 34', {'floors': 5, 'events': [['arrive', 3, 'up'], ['arrive', 0, 'idle'], ['arrive', 3, 'idle'], ['arrive', 1, 'idle'], ['arrive', 0, 'down'], ['arrive', 2, 'down'], ['arrive', 1, 'down'], ['press', 1, 'down'], ['press', 4, 'up'], ['arrive', 3, 'down']]}, {'log': ['served:', 'served:', 'served:', 'served:', 'served:', 'served:', 'served:', 'lit', 'ignored', 'served:'], 'pending': [[1, 'down']]}), ('control 37', {'floors': 7, 'events': [['arrive', 4, 'up'], ['press', 1, 'up'], ['arrive', 2, 'down'], ['press', 4, 'down'], ['arrive', 0, 'idle'], ['press', 4, 'down']]}, {'log': ['served:', 'lit', 'served:', 'lit', 'served:', 'lit'], 'pending': [[1, 'up'], [4, 'down']]}), ('control 40', {'floors': 9, 'events': [['arrive', 1, 'idle'], ['press', 7, 'down'], ['arrive', 0, 'down'], ['press', -1, 'up']]}, {'log': ['served:', 'lit', 'served:', 'ignored'], 'pending': [[7, 'down']]})], [('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 39', {'floors': 7, 'events': [['press', 4, 'down'], ['press', 1, 'up'], ['press', 6, 'down'], ['arrive', 6, 'up'], ['arrive', 0, 'up'], ['press', 6, 'down'], ['arrive', 1, 'idle'], ['press', 2, 'down']]}, {'log': ['lit', 'lit', 'lit', 'served:down', 'served:', 'lit', 'served:up', 'lit'], 'pending': [[2, 'down'], [4, 'down'], [6, 'down']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: down button at the lobby', {'floors': 6, 'events': [['press', 0, 'down'], ['press', 0, 'up']]}, {'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}), ('control 45', {'floors': 5, 'events': [['arrive', 4, 'up'], ['arrive', 2, 'up'], ['press', -1, 'up'], ['press', 4, 'down'], ['press', 3, 'up'], ['press', 4, 'down'], ['arrive', 2, 'up']]}, {'log': ['served:', 'served:', 'ignored', 'lit', 'lit', 'lit', 'served:'], 'pending': [[3, 'up'], [4, 'down']]}), ('control 48', {'floors': 9, 'events': [['arrive', 8, 'idle'], ['press', 2, 'down'], ['press', 2, 'down'], ['press', 9, 'down'], ['press', -1, 'up'], ['arrive', 0, 'idle'], ['press', 8, 'down']]}, {'log': ['served:', 'lit', 'lit', 'ignored', 'ignored', 'served:', 'lit'], 'pending': [[2, 'down'], [8, 'down']]}), ('control 51', {'floors': 7, 'events': [['press', 7, 'down'], ['press', 4, 'down'], ['press', 6, 'down']]}, {'log': ['ignored', 'lit', 'lit'], 'pending': [[4, 'down'], [6, 'down']]})]]
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: up car at the top floor reverses	`{'log': ['lit', 'served:down'], 'pending': []}`	`{'log': ['lit', 'served:down'], 'pending': []}`	Passed
regression: down car at the lobby reverses	`{'log': ['lit', 'served:'], 'pending': [[0, 'up']]}`	`{'log': ['lit', 'served:up'], 'pending': []}`	Failed
sampled regression 26	`{'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:', 'lit'], 'pending': [[0, 'up'], [3, 'up'], [4, 'down']]}`	`{'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}`	Failed
boundary: up button at the top floor	`{'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}`	`{'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}`	Passed
boundary: down button at the lobby	`{'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}`	`{'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}`	Passed
sampled regression 1	`{'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}`	`{'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}`	Passed
control 4	`{'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}`	`{'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}`	Passed
control 7	`{'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]}`	`{'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]}`	Passed

SHA-256 / 3149eeaf2b2f9996c65f10629dcaf54a7479c6e07942138ce534ce6934a9d190

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(x):
    top = x['floors'] - 1
    calls = set()
    out = []
    for kind, f, d in x['events']:
        if kind == 'press':
            if not (0 <= f <= top) or (f == top and d == 'up') or (f == 0 and d == 'down'):
                out.append('ignored')
                continue
            calls.add((f, d))
            out.append('lit')
        else:
            both = d == 'idle' or f in (0, top)
            served = sorted(c for c in calls if c[0] == f and (both or c[1] == d))
            for c in served:
                calls.discard(c)
            out.append('served:' + ','.join(c[1] for c in served))
    return {'log': out, 'pending': sorted([list(c) for c in calls])}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: up button at the top floor', {'floors': 6, 'events': [['press', 5, 'up'], ['press', 5, 'down']]}, {'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}), ('boundary: down button at the lobby', {'floors': 6, 'events': [['press', 0, 'down'], ['press', 0, 'up']]}, {'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}), ('sampled regression 1', {'floors': 5, 'events': [['press', -1, 'down'], ['press', 4, 'down'], ['press', 4, 'down'], ['arrive', 3, 'idle'], ['press', 0, 'up'], ['press', 1, 'down'], ['press', 2, 'up'], ['arrive', 4, 'up']]}, {'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}), ('control 4', {'floors': 6, 'events': [['arrive', 2, 'up'], ['press', 1, 'up'], ['press', 5, 'down'], ['press', 1, 'down'], ['arrive', 4, 'up'], ['arrive', 3, 'up'], ['arrive', 0, 'idle'], ['arrive', 0, 'idle'], ['arrive', 5, 'down'], ['press', 0, 'down']]}, {'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}), ('control 7', {'floors': 5, 'events': [['arrive', 4, 'idle'], ['press', 3, 'down'], ['arrive', 2, 'down'], ['arrive', 3, 'idle'], ['arrive', 3, 'up'], ['press', 1, 'down']]}, {'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]})], [('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: idle car serves both lamps', {'floors': 6, 'events': [['press', 3, 'up'], ['press', 3, 'down'], ['arrive', 3, 'idle']]}, {'log': ['lit', 'lit', 'served:down,up'], 'pending': []}), ('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('boundary: floor above the shaft', {'floors': 6, 'events': [['press', 6, 'down'], ['press', -1, 'up']]}, {'log': ['ignored', 'ignored'], 'pending': []}), ('control 12', {'floors': 7, 'events': [['press', 5, 'up'], ['press', 6, 'down'], ['arrive', 2, 'idle'], ['arrive', 5, 'down'], ['press', 6, 'up']]}, {'log': ['lit', 'lit', 'served:', 'served:', 'ignored'], 'pending': [[5, 'up'], [6, 'down']]}), ('control 15', {'floors': 10, 'events': [['press', 9, 'up'], ['arrive', 5, 'down'], ['arrive', 9, 'up'], ['press', 0, 'down'], ['press', 10, 'down'], ['press', 2, 'down']]}, {'log': ['ignored', 'served:', 'served:', 'ignored', 'ignored', 'lit'], 'pending': [[2, 'down']]}), ('control 18', {'floors': 9, 'events': [['press', 5, 'down'], ['press', 1, 'down'], ['press', 7, 'down'], ['arrive', 0, 'up'], ['arrive', 3, 'up'], ['press', 7, 'up'], ['press', 5, 'up'], ['press', 8, 'up'], ['arrive', 8, 'up']]}, {'log': ['lit', 'lit', 'lit', 'served:', 'served:', 'lit', 'lit', 'ignored', 'served:'], 'pending': [[1, 'down'], [5, 'down'], [5, 'up'], [7, 'down'], [7, 'up']]})], [('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 77', {'floors': 6, 'events': [['press', 0, 'up'], ['press', -1, 'up'], ['arrive', 0, 'down'], ['arrive', 5, 'idle'], ['press', 3, 'up'], ['press', 5, 'up'], ['arrive', 5, 'up']]}, {'log': ['lit', 'ignored', 'served:up', 'served:', 'lit', 'ignored', 'served:'], 'pending': [[3, 'up']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: floor above the shaft', {'floors': 6, 'events': [['press', 6, 'down'], ['press', -1, 'up']]}, {'log': ['ignored', 'ignored'], 'pending': []}), ('control 23', {'floors': 10, 'events': [['press', 5, 'up'], ['press', 1, 'up'], ['arrive', 9, 'up'], ['arrive', 9, 'idle'], ['press', 9, 'up'], ['press', 9, 'up'], ['arrive', 1, 'down'], ['arrive', 9, 'up'], ['press', 4, 'up'], ['press', 4, 'down']]}, {'log': ['lit', 'lit', 'served:', 'served:', 'ignored', 'ignored', 'served:', 'served:', 'lit', 'lit'], 'pending': [[1, 'up'], [4, 'down'], [4, 'up'], [5, 'up']]}), ('control 29', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'idle'], ['press', 5, 'up'], ['press', 6, 'down'], ['press', 0, 'up'], ['arrive', 5, 'down']]}, {'log': ['lit', 'served:up', 'ignored', 'ignored', 'lit', 'served:'], 'pending': [[0, 'up']]}), ('control 32', {'floors': 5, 'events': [['press', -1, 'up'], ['arrive', 4, 'idle'], ['press', 2, 'up'], ['press', -1, 'up']]}, {'log': ['ignored', 'served:', 'lit', 'ignored'], 'pending': [[2, 'up']]})], [('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 60', {'floors': 8, 'events': [['press', 0, 'up'], ['arrive', 0, 'down'], ['arrive', 1, 'idle'], ['press', 7, 'down'], ['press', 4, 'down'], ['arrive', 5, 'idle'], ['arrive', 5, 'idle'], ['press', 7, 'up']]}, {'log': ['lit', 'served:up', 'served:', 'lit', 'lit', 'served:', 'served:', 'ignored'], 'pending': [[4, 'down'], [7, 'down']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: passing car in the other direction', {'floors': 6, 'events': [['press', 2, 'down'], ['arrive', 2, 'up']]}, {'log': ['lit', 'served:'], 'pending': [[2, 'down']]}), ('boundary: up button at the top floor', {'floors': 6, 'events': [['press', 5, 'up'], ['press', 5, 'down']]}, {'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}), ('control 34', {'floors': 5, 'events': [['arrive', 3, 'up'], ['arrive', 0, 'idle'], ['arrive', 3, 'idle'], ['arrive', 1, 'idle'], ['arrive', 0, 'down'], ['arrive', 2, 'down'], ['arrive', 1, 'down'], ['press', 1, 'down'], ['press', 4, 'up'], ['arrive', 3, 'down']]}, {'log': ['served:', 'served:', 'served:', 'served:', 'served:', 'served:', 'served:', 'lit', 'ignored', 'served:'], 'pending': [[1, 'down']]}), ('control 37', {'floors': 7, 'events': [['arrive', 4, 'up'], ['press', 1, 'up'], ['arrive', 2, 'down'], ['press', 4, 'down'], ['arrive', 0, 'idle'], ['press', 4, 'down']]}, {'log': ['served:', 'lit', 'served:', 'lit', 'served:', 'lit'], 'pending': [[1, 'up'], [4, 'down']]}), ('control 40', {'floors': 9, 'events': [['arrive', 1, 'idle'], ['press', 7, 'down'], ['arrive', 0, 'down'], ['press', -1, 'up']]}, {'log': ['served:', 'lit', 'served:', 'ignored'], 'pending': [[7, 'down']]})], [('regression: up car at the top floor reverses', {'floors': 6, 'events': [['press', 5, 'down'], ['arrive', 5, 'up']]}, {'log': ['lit', 'served:down'], 'pending': []}), ('regression: down car at the lobby reverses', {'floors': 6, 'events': [['press', 0, 'up'], ['arrive', 0, 'down']]}, {'log': ['lit', 'served:up'], 'pending': []}), ('sampled regression 39', {'floors': 7, 'events': [['press', 4, 'down'], ['press', 1, 'up'], ['press', 6, 'down'], ['arrive', 6, 'up'], ['arrive', 0, 'up'], ['press', 6, 'down'], ['arrive', 1, 'idle'], ['press', 2, 'down']]}, {'log': ['lit', 'lit', 'lit', 'served:down', 'served:', 'lit', 'served:up', 'lit'], 'pending': [[2, 'down'], [4, 'down'], [6, 'down']]}), ('sampled regression 26', {'floors': 5, 'events': [['press', 4, 'down'], ['press', 0, 'down'], ['arrive', 0, 'up'], ['press', 3, 'up'], ['press', 3, 'up'], ['press', 0, 'up'], ['arrive', 4, 'idle'], ['arrive', 0, 'down'], ['press', 4, 'down']]}, {'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}), ('boundary: down button at the lobby', {'floors': 6, 'events': [['press', 0, 'down'], ['press', 0, 'up']]}, {'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}), ('control 45', {'floors': 5, 'events': [['arrive', 4, 'up'], ['arrive', 2, 'up'], ['press', -1, 'up'], ['press', 4, 'down'], ['press', 3, 'up'], ['press', 4, 'down'], ['arrive', 2, 'up']]}, {'log': ['served:', 'served:', 'ignored', 'lit', 'lit', 'lit', 'served:'], 'pending': [[3, 'up'], [4, 'down']]}), ('control 48', {'floors': 9, 'events': [['arrive', 8, 'idle'], ['press', 2, 'down'], ['press', 2, 'down'], ['press', 9, 'down'], ['press', -1, 'up'], ['arrive', 0, 'idle'], ['press', 8, 'down']]}, {'log': ['served:', 'lit', 'lit', 'ignored', 'ignored', 'served:', 'lit'], 'pending': [[2, 'down'], [8, 'down']]}), ('control 51', {'floors': 7, 'events': [['press', 7, 'down'], ['press', 4, 'down'], ['press', 6, 'down']]}, {'log': ['ignored', 'lit', 'lit'], 'pending': [[4, 'down'], [6, 'down']]})]]
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: up car at the top floor reverses	`{'log': ['lit', 'served:down'], 'pending': []}`	`{'log': ['lit', 'served:down'], 'pending': []}`	Passed
regression: down car at the lobby reverses	`{'log': ['lit', 'served:up'], 'pending': []}`	`{'log': ['lit', 'served:up'], 'pending': []}`	Passed
sampled regression 26	`{'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}`	`{'log': ['lit', 'ignored', 'served:', 'lit', 'lit', 'lit', 'served:down', 'served:up', 'lit'], 'pending': [[3, 'up'], [4, 'down']]}`	Passed
boundary: up button at the top floor	`{'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}`	`{'log': ['ignored', 'lit'], 'pending': [[5, 'down']]}`	Passed
boundary: down button at the lobby	`{'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}`	`{'log': ['ignored', 'lit'], 'pending': [[0, 'up']]}`	Passed
sampled regression 1	`{'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}`	`{'log': ['ignored', 'lit', 'lit', 'served:', 'lit', 'lit', 'lit', 'served:down'], 'pending': [[0, 'up'], [1, 'down'], [2, 'up']]}`	Passed
control 4	`{'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}`	`{'log': ['served:', 'lit', 'lit', 'lit', 'served:', 'served:', 'served:', 'served:', 'served:down', 'ignored'], 'pending': [[1, 'down'], [1, 'up']]}`	Passed
control 7	`{'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]}`	`{'log': ['served:', 'lit', 'served:', 'served:down', 'served:', 'lit'], 'pending': [[1, 'down']]}`	Passed

SHA-256 / f55684a733bd4f6b5bbd46e2cb005978998589115ad8065fac16ba5ed3b57373

Verification & scope

Stipulated toy lift-control contract for a bounded teaching model; it makes no claim of conformance to any lift code or vendor dispatcher and omits real safety cases. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:47:56.196170+00:00.

Case digest / c59659dfc44bb1dd8f7c8d03706cee81610286a998851fc6f8010cc38685ea5a