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FA-67646 / Elevator dispatch scheduling / Open access

Door obstruction reopen and nudging: safety edge during nudging · case 01

The safety edge is ignored while the door nudges.

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

ROOT CAUSE

Edge contacts are suppressed together with the light curtain during nudging.

THE FAILURE

Edge contacts are suppressed together with the light curtain during nudging.

Unsuccessful approach: Cancelling nudging on an edge contact lets the curtain count start over.

Case contract

During a door cycle each light-curtain obstruction reopens the doors and counts; the third obstruction, or an obstruction while the curtain has been blocked continuously for 20 s or more since the first unbroken obstruction, starts nudging (slow close, curtain ignored). While nudging, curtain obstructions are ignored. The mechanical safety edge always reopens and does not affect counting. unblock ends a continuous blockage. closed ends the cycle and resets everything.

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):
    count = 0
    nudge = False
    block_start = None
    out = []
    for t, ev in x['events']:
        if ev == 'obstruct':
            if block_start is None:
                block_start = t
            if nudge:
                out.append('ignored')
            else:
                count += 1
                if count >= 3 or t - block_start >= 20:
                    nudge = True
                    out.append('nudge')
                else:
                    out.append('reopen')
        elif ev == 'unblock':
            block_start = None
        elif ev == 'edge':
            out.append('ignored' if nudge else 'reopen')
        elif ev == 'closed':
            count = 0
            nudge = False
            block_start = None
            out.append('done')
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 22', {'events': [[5, 'closed'], [7, 'obstruct'], [9, 'obstruct'], [14, 'obstruct'], [19, 'edge'], [20, 'edge'], [32, 'unblock']]}, ['done', 'reopen', 'reopen', 'nudge', 'reopen', 'reopen']), ('control 1', {'events': [[8, 'obstruct'], [13, 'closed'], [18, 'obstruct'], [26, 'edge'], [28, 'obstruct'], [29, 'obstruct'], [41, 'obstruct'], [42, 'obstruct'], [54, 'obstruct'], [66, 'closed']]}, ['reopen', 'done', 'reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'ignored', 'done']), ('boundary: third obstruction', {'events': [[1, 'obstruct'], [2, 'unblock'], [3, 'obstruct'], [4, 'unblock'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge']), ('boundary: edge contacts do not count', {'events': [[1, 'obstruct'], [2, 'edge'], [3, 'unblock'], [4, 'obstruct'], [5, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('control 4', {'events': [[5, 'edge'], [10, 'unblock'], [11, 'obstruct'], [19, 'closed']]}, ['reopen', 'reopen', 'done']), ('control 7', {'events': [[2, 'unblock'], [10, 'edge'], [18, 'obstruct'], [23, 'unblock'], [28, 'edge'], [33, 'obstruct']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('control 10', {'events': [[8, 'edge'], [13, 'obstruct'], [18, 'edge'], [30, 'unblock'], [35, 'obstruct'], [40, 'obstruct'], [42, 'unblock']]}, ['reopen', 'reopen', 'reopen', 'reopen', 'nudge'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 77', {'events': [[5, 'obstruct'], [13, 'obstruct'], [25, 'obstruct'], [33, 'obstruct'], [41, 'obstruct'], [53, 'edge'], [54, 'edge']]}, ['reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'reopen', 'reopen']), ('sampled regression 33', {'events': [[5, 'obstruct'], [17, 'unblock'], [18, 'obstruct'], [20, 'unblock'], [32, 'edge'], [34, 'edge'], [46, 'unblock'], [54, 'obstruct'], [62, 'edge'], [70, 'closed']]}, ['reopen', 'reopen', 'reopen', 'reopen', 'nudge', 'reopen', 'done']), ('boundary: edge contacts do not count', {'events': [[1, 'obstruct'], [2, 'edge'], [3, 'unblock'], [4, 'obstruct'], [5, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('boundary: new cycle after closing', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'closed'], [4, 'obstruct'], [5, 'unblock']]}, ['reopen', 'reopen', 'done', 'reopen']), ('control 12', {'events': [[5, 'obstruct'], [13, 'edge'], [15, 'unblock'], [16, 'obstruct'], [21, 'unblock'], [22, 'edge'], [30, 'closed'], [32, 'obstruct'], [44, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen', 'done', 'reopen', 'reopen']), ('sampled regression 15', {'events': [[8, 'obstruct'], [9, 'obstruct'], [10, 'obstruct'], [11, 'unblock'], [16, 'obstruct'], [24, 'obstruct'], [29, 'edge']]}, ['reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'reopen']), ('control 18', {'events': [[12, 'obstruct'], [20, 'obstruct'], [22, 'obstruct']]}, ['reopen', 'reopen', 'nudge'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 67', {'events': [[12, 'obstruct'], [20, 'obstruct'], [28, 'edge'], [33, 'obstruct'], [41, 'obstruct'], [53, 'edge'], [65, 'edge'], [67, 'edge'], [75, 'unblock'], [76, 'obstruct']]}, ['reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'reopen', 'reopen', 'reopen', 'ignored']), ('sampled regression 76', {'events': [[2, 'obstruct'], [4, 'obstruct'], [5, 'obstruct'], [13, 'edge'], [15, 'edge'], [20, 'obstruct'], [22, 'obstruct'], [30, 'obstruct'], [42, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'reopen', 'ignored', 'ignored', 'ignored', 'ignored']), ('boundary: curtain held for twenty seconds', {'events': [[0, 'obstruct'], [20, 'obstruct']]}, ['reopen', 'nudge']), ('boundary: curtain broken then blocked again', {'events': [[0, 'obstruct'], [5, 'unblock'], [15, 'obstruct'], [26, 'obstruct']]}, ['reopen', 'reopen', 'nudge']), ('control 23', {'events': [[1, 'unblock'], [6, 'unblock'], [18, 'obstruct'], [30, 'closed']]}, ['reopen', 'done']), ('control 26', {'events': [[12, 'closed'], [13, 'closed'], [15, 'obstruct'], [17, 'obstruct'], [19, 'obstruct']]}, ['done', 'done', 'reopen', 'reopen', 'nudge']), ('control 29', {'events': [[8, 'edge'], [10, 'obstruct'], [12, 'obstruct'], [20, 'closed']]}, ['reopen', 'reopen', 'reopen', 'done'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 15', {'events': [[8, 'obstruct'], [9, 'obstruct'], [10, 'obstruct'], [11, 'unblock'], [16, 'obstruct'], [24, 'obstruct'], [29, 'edge']]}, ['reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'reopen']), ('control 17', {'events': [[5, 'unblock'], [13, 'unblock'], [14, 'closed'], [26, 'obstruct'], [34, 'edge'], [36, 'obstruct'], [48, 'unblock'], [60, 'obstruct'], [72, 'unblock']]}, ['done', 'reopen', 'reopen', 'reopen', 'nudge']), ('boundary: closing clears nudging', {'events': [[0, 'obstruct'], [1, 'obstruct'], [2, 'obstruct'], [3, 'closed'], [4, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'done', 'reopen']), ('boundary: third obstruction', {'events': [[1, 'obstruct'], [2, 'unblock'], [3, 'obstruct'], [4, 'unblock'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge']), ('control 34', {'events': [[8, 'edge'], [16, 'obstruct'], [24, 'obstruct'], [36, 'closed'], [48, 'obstruct'], [60, 'obstruct'], [62, 'obstruct'], [64, 'unblock'], [72, 'obstruct'], [80, 'unblock']]}, ['reopen', 'reopen', 'reopen', 'done', 'reopen', 'reopen', 'nudge', 'ignored']), ('control 37', {'events': [[2, 'closed'], [4, 'closed'], [9, 'obstruct'], [21, 'edge']]}, ['done', 'done', 'reopen', 'reopen']), ('control 40', {'events': [[2, 'closed'], [7, 'obstruct'], [15, 'edge'], [16, 'obstruct'], [18, 'closed']]}, ['done', 'reopen', 'reopen', 'reopen', 'done'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 76', {'events': [[2, 'obstruct'], [4, 'obstruct'], [5, 'obstruct'], [13, 'edge'], [15, 'edge'], [20, 'obstruct'], [22, 'obstruct'], [30, 'obstruct'], [42, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'reopen', 'ignored', 'ignored', 'ignored', 'ignored']), ('sampled regression 67', {'events': [[12, 'obstruct'], [20, 'obstruct'], [28, 'edge'], [33, 'obstruct'], [41, 'obstruct'], [53, 'edge'], [65, 'edge'], [67, 'edge'], [75, 'unblock'], [76, 'obstruct']]}, ['reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'reopen', 'reopen', 'reopen', 'ignored']), ('boundary: edge contacts do not count', {'events': [[1, 'obstruct'], [2, 'edge'], [3, 'unblock'], [4, 'obstruct'], [5, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('boundary: new cycle after closing', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'closed'], [4, 'obstruct'], [5, 'unblock']]}, ['reopen', 'reopen', 'done', 'reopen']), ('control 45', {'events': [[5, 'edge'], [17, 'closed'], [22, 'obstruct'], [24, 'closed']]}, ['reopen', 'done', 'reopen', 'done']), ('control 48', {'events': [[2, 'obstruct'], [7, 'obstruct'], [15, 'obstruct'], [27, 'obstruct'], [35, 'unblock']]}, ['reopen', 'reopen', 'nudge', 'ignored']), ('control 51', {'events': [[8, 'closed'], [9, 'closed'], [14, 'obstruct'], [26, 'closed'], [38, 'obstruct']]}, ['done', 'done', 'reopen', 'done', 'reopen'])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: safety edge while nudging['reopen', 'reopen', 'nudge', 'ignored', 'ignored']['reopen', 'reopen', 'nudge', 'reopen', 'ignored']Failed
sampled regression 22['done', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored']['done', 'reopen', 'reopen', 'nudge', 'reopen', 'reopen']Failed
control 1['reopen', 'done', 'reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'ignored', 'done']['reopen', 'done', 'reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'ignored', 'done']Passed
boundary: third obstruction['reopen', 'reopen', 'nudge']['reopen', 'reopen', 'nudge']Passed
boundary: edge contacts do not count['reopen', 'reopen', 'reopen', 'reopen']['reopen', 'reopen', 'reopen', 'reopen']Passed
control 4['reopen', 'reopen', 'done']['reopen', 'reopen', 'done']Passed
control 7['reopen', 'reopen', 'reopen', 'reopen']['reopen', 'reopen', 'reopen', 'reopen']Passed
control 10['reopen', 'reopen', 'reopen', 'reopen', 'nudge']['reopen', 'reopen', 'reopen', 'reopen', 'nudge']Passed

SHA-256 / 56c7896e9a50bebb1e5bd6a1e14e4bcd9cfc8c07545531d29b4fa3000d2005e6

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(x):
    count = 0
    nudge = False
    block_start = None
    out = []
    for t, ev in x['events']:
        if ev == 'obstruct':
            if block_start is None:
                block_start = t
            if nudge:
                out.append('ignored')
            else:
                count += 1
                if count >= 3 or t - block_start >= 20:
                    nudge = True
                    out.append('nudge')
                else:
                    out.append('reopen')
        elif ev == 'unblock':
            block_start = None
        elif ev == 'edge':
            out.append('reopen')
            nudge = False
            count = 0
        elif ev == 'closed':
            count = 0
            nudge = False
            block_start = None
            out.append('done')
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 22', {'events': [[5, 'closed'], [7, 'obstruct'], [9, 'obstruct'], [14, 'obstruct'], [19, 'edge'], [20, 'edge'], [32, 'unblock']]}, ['done', 'reopen', 'reopen', 'nudge', 'reopen', 'reopen']), ('control 1', {'events': [[8, 'obstruct'], [13, 'closed'], [18, 'obstruct'], [26, 'edge'], [28, 'obstruct'], [29, 'obstruct'], [41, 'obstruct'], [42, 'obstruct'], [54, 'obstruct'], [66, 'closed']]}, ['reopen', 'done', 'reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'ignored', 'done']), ('boundary: third obstruction', {'events': [[1, 'obstruct'], [2, 'unblock'], [3, 'obstruct'], [4, 'unblock'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge']), ('boundary: edge contacts do not count', {'events': [[1, 'obstruct'], [2, 'edge'], [3, 'unblock'], [4, 'obstruct'], [5, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('control 4', {'events': [[5, 'edge'], [10, 'unblock'], [11, 'obstruct'], [19, 'closed']]}, ['reopen', 'reopen', 'done']), ('control 7', {'events': [[2, 'unblock'], [10, 'edge'], [18, 'obstruct'], [23, 'unblock'], [28, 'edge'], [33, 'obstruct']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('control 10', {'events': [[8, 'edge'], [13, 'obstruct'], [18, 'edge'], [30, 'unblock'], [35, 'obstruct'], [40, 'obstruct'], [42, 'unblock']]}, ['reopen', 'reopen', 'reopen', 'reopen', 'nudge'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 77', {'events': [[5, 'obstruct'], [13, 'obstruct'], [25, 'obstruct'], [33, 'obstruct'], [41, 'obstruct'], [53, 'edge'], [54, 'edge']]}, ['reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'reopen', 'reopen']), ('sampled regression 33', {'events': [[5, 'obstruct'], [17, 'unblock'], [18, 'obstruct'], [20, 'unblock'], [32, 'edge'], [34, 'edge'], [46, 'unblock'], [54, 'obstruct'], [62, 'edge'], [70, 'closed']]}, ['reopen', 'reopen', 'reopen', 'reopen', 'nudge', 'reopen', 'done']), ('boundary: edge contacts do not count', {'events': [[1, 'obstruct'], [2, 'edge'], [3, 'unblock'], [4, 'obstruct'], [5, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('boundary: new cycle after closing', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'closed'], [4, 'obstruct'], [5, 'unblock']]}, ['reopen', 'reopen', 'done', 'reopen']), ('control 12', {'events': [[5, 'obstruct'], [13, 'edge'], [15, 'unblock'], [16, 'obstruct'], [21, 'unblock'], [22, 'edge'], [30, 'closed'], [32, 'obstruct'], [44, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen', 'done', 'reopen', 'reopen']), ('sampled regression 15', {'events': [[8, 'obstruct'], [9, 'obstruct'], [10, 'obstruct'], [11, 'unblock'], [16, 'obstruct'], [24, 'obstruct'], [29, 'edge']]}, ['reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'reopen']), ('control 18', {'events': [[12, 'obstruct'], [20, 'obstruct'], [22, 'obstruct']]}, ['reopen', 'reopen', 'nudge'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 67', {'events': [[12, 'obstruct'], [20, 'obstruct'], [28, 'edge'], [33, 'obstruct'], [41, 'obstruct'], [53, 'edge'], [65, 'edge'], [67, 'edge'], [75, 'unblock'], [76, 'obstruct']]}, ['reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'reopen', 'reopen', 'reopen', 'ignored']), ('sampled regression 76', {'events': [[2, 'obstruct'], [4, 'obstruct'], [5, 'obstruct'], [13, 'edge'], [15, 'edge'], [20, 'obstruct'], [22, 'obstruct'], [30, 'obstruct'], [42, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'reopen', 'ignored', 'ignored', 'ignored', 'ignored']), ('boundary: curtain held for twenty seconds', {'events': [[0, 'obstruct'], [20, 'obstruct']]}, ['reopen', 'nudge']), ('boundary: curtain broken then blocked again', {'events': [[0, 'obstruct'], [5, 'unblock'], [15, 'obstruct'], [26, 'obstruct']]}, ['reopen', 'reopen', 'nudge']), ('control 23', {'events': [[1, 'unblock'], [6, 'unblock'], [18, 'obstruct'], [30, 'closed']]}, ['reopen', 'done']), ('control 26', {'events': [[12, 'closed'], [13, 'closed'], [15, 'obstruct'], [17, 'obstruct'], [19, 'obstruct']]}, ['done', 'done', 'reopen', 'reopen', 'nudge']), ('control 29', {'events': [[8, 'edge'], [10, 'obstruct'], [12, 'obstruct'], [20, 'closed']]}, ['reopen', 'reopen', 'reopen', 'done'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 15', {'events': [[8, 'obstruct'], [9, 'obstruct'], [10, 'obstruct'], [11, 'unblock'], [16, 'obstruct'], [24, 'obstruct'], [29, 'edge']]}, ['reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'reopen']), ('control 17', {'events': [[5, 'unblock'], [13, 'unblock'], [14, 'closed'], [26, 'obstruct'], [34, 'edge'], [36, 'obstruct'], [48, 'unblock'], [60, 'obstruct'], [72, 'unblock']]}, ['done', 'reopen', 'reopen', 'reopen', 'nudge']), ('boundary: closing clears nudging', {'events': [[0, 'obstruct'], [1, 'obstruct'], [2, 'obstruct'], [3, 'closed'], [4, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'done', 'reopen']), ('boundary: third obstruction', {'events': [[1, 'obstruct'], [2, 'unblock'], [3, 'obstruct'], [4, 'unblock'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge']), ('control 34', {'events': [[8, 'edge'], [16, 'obstruct'], [24, 'obstruct'], [36, 'closed'], [48, 'obstruct'], [60, 'obstruct'], [62, 'obstruct'], [64, 'unblock'], [72, 'obstruct'], [80, 'unblock']]}, ['reopen', 'reopen', 'reopen', 'done', 'reopen', 'reopen', 'nudge', 'ignored']), ('control 37', {'events': [[2, 'closed'], [4, 'closed'], [9, 'obstruct'], [21, 'edge']]}, ['done', 'done', 'reopen', 'reopen']), ('control 40', {'events': [[2, 'closed'], [7, 'obstruct'], [15, 'edge'], [16, 'obstruct'], [18, 'closed']]}, ['done', 'reopen', 'reopen', 'reopen', 'done'])], [('regression: safety edge while nudging', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'obstruct'], [4, 'edge'], [5, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'ignored']), ('sampled regression 76', {'events': [[2, 'obstruct'], [4, 'obstruct'], [5, 'obstruct'], [13, 'edge'], [15, 'edge'], [20, 'obstruct'], [22, 'obstruct'], [30, 'obstruct'], [42, 'obstruct']]}, ['reopen', 'reopen', 'nudge', 'reopen', 'reopen', 'ignored', 'ignored', 'ignored', 'ignored']), ('sampled regression 67', {'events': [[12, 'obstruct'], [20, 'obstruct'], [28, 'edge'], [33, 'obstruct'], [41, 'obstruct'], [53, 'edge'], [65, 'edge'], [67, 'edge'], [75, 'unblock'], [76, 'obstruct']]}, ['reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'reopen', 'reopen', 'reopen', 'ignored']), ('boundary: edge contacts do not count', {'events': [[1, 'obstruct'], [2, 'edge'], [3, 'unblock'], [4, 'obstruct'], [5, 'edge']]}, ['reopen', 'reopen', 'reopen', 'reopen']), ('boundary: new cycle after closing', {'events': [[1, 'obstruct'], [2, 'obstruct'], [3, 'closed'], [4, 'obstruct'], [5, 'unblock']]}, ['reopen', 'reopen', 'done', 'reopen']), ('control 45', {'events': [[5, 'edge'], [17, 'closed'], [22, 'obstruct'], [24, 'closed']]}, ['reopen', 'done', 'reopen', 'done']), ('control 48', {'events': [[2, 'obstruct'], [7, 'obstruct'], [15, 'obstruct'], [27, 'obstruct'], [35, 'unblock']]}, ['reopen', 'reopen', 'nudge', 'ignored']), ('control 51', {'events': [[8, 'closed'], [9, 'closed'], [14, 'obstruct'], [26, 'closed'], [38, 'obstruct']]}, ['done', 'done', 'reopen', 'done', 'reopen'])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
regression: safety edge while nudging['reopen', 'reopen', 'nudge', 'reopen', 'reopen']['reopen', 'reopen', 'nudge', 'reopen', 'ignored']Failed
sampled regression 22['done', 'reopen', 'reopen', 'nudge', 'reopen', 'reopen']['done', 'reopen', 'reopen', 'nudge', 'reopen', 'reopen']Passed
control 1['reopen', 'done', 'reopen', 'reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'done']['reopen', 'done', 'reopen', 'reopen', 'reopen', 'nudge', 'ignored', 'ignored', 'ignored', 'done']Failed
boundary: third obstruction['reopen', 'reopen', 'nudge']['reopen', 'reopen', 'nudge']Passed
boundary: edge contacts do not count['reopen', 'reopen', 'reopen', 'reopen']['reopen', 'reopen', 'reopen', 'reopen']Passed
control 4['reopen', 'reopen', 'done']['reopen', 'reopen', 'done']Passed
control 7['reopen', 'reopen', 'reopen', 'reopen']['reopen', 'reopen', 'reopen', 'reopen']Passed
control 10['reopen', 'reopen', 'reopen', 'reopen', 'reopen']['reopen', 'reopen', 'reopen', 'reopen', 'nudge']Failed

SHA-256 / a194567bc68558251f0f700e2bc9ba05a1b76a249486d8b90cfa4dc432f38c93

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

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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 2026-09-29T14:47:54.840532+00:00.

Case digest / 11f9e726c2e192e996f7a159397317dd4502987f71ef4a2d2f1bd4a0ee1d0a29