FA-68161 / Traffic signal timing plans / Open access

Railroad preemption entry timing: the normal minimum green is honoured during preemption entry · case 01

Railroad preemption entry timing returns a wrong result when the normal minimum green is honoured during preemption entry.

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

ROOT CAUSE

The controller times the full normal minimum green before leaving for the track clearance phase, delaying it.

THE FAILURE

The controller times the full normal minimum green before leaving for the track clearance phase, delaying it.

Unsuccessful approach: Using the preempt minimum without subtracting elapsed green re-times it from zero.

Case contract

Input {state: green|yellow|red (red = all-red clearance), elapsed, min_green, preempt_min_green, yellow, red, fdw, ped: none|walk|fdw, ped_elapsed, ped_truncate, track_current}. If the track clearance phase is already green the answer is [0, 0]. In all-red the remaining red is timed; in yellow the remaining yellow and full red are timed. In green the hold is the larger of the remaining preempt minimum green (not the normal minimum) and the pedestrian time: walk is abandoned and FDW is timed in full, or skipped when ped_truncate; an active FDW completes its remainder unless truncated. Return [seconds until track clearance green, green hold].

Why this case matters

Signal timing arithmetic is exact and integer or rational; a wrong rule silently produces unsafe or inefficient timing plans.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(x):
    st, el = x['state'], x['elapsed']
    y, r, f = x['yellow'], x['red'], x['fdw']
    if st == 'green' and x['track_current']:
        return [0, 0]
    if st == 'red':
        return [max(0, r - el), 0]
    if st == 'yellow':
        return [max(0, y - el) + r, 0]
    ped = 0
    if x['ped'] == 'walk':
        ped = 0 if x['ped_truncate'] else f
    elif x['ped'] == 'fdw':
        ped = 0 if x['ped_truncate'] else max(0, f - x['ped_elapsed'])
    hold = max(ped, max(0, x['min_green'] - el))
    return [hold + y + r, hold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'state': 'green', 'elapsed': 2, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 6, 'red': 2, 'fdw': 11, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [15, 7]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 3, 'min_green': 8, 'preempt_min_green': 4, 'yellow': 6, 'red': 2, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'green', 'elapsed': 19, 'min_green': 19, 'preempt_min_green': 7, 'yellow': 6, 'red': 2, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [8, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 14, 'min_green': 17, 'preempt_min_green': 4, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'walk', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 12, 'preempt_min_green': 4, 'yellow': 3, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 15, 'ped_truncate': True, 'track_current': False}, [2, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 9, 'preempt_min_green': 4, 'yellow': 4, 'red': 3, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 7, 'yellow': 3, 'red': 2, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [30, 25]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'yellow', 'elapsed': 6, 'min_green': 10, 'preempt_min_green': 2, 'yellow': 6, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 7, 'min_green': 13, 'preempt_min_green': 3, 'yellow': 4, 'red': 1, 'fdw': 17, 'ped': 'walk', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [5, 0]), ({'state': 'green', 'elapsed': 14, 'min_green': 19, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 16, 'ped': 'walk', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [22, 16]), ({'state': 'green', 'elapsed': 0, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 21, 'ped': 'fdw', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [16, 9]), ({'state': 'green', 'elapsed': 19, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 2, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [6, 0])], [({'state': 'green', 'elapsed': 14, 'min_green': 10, 'preempt_min_green': 9, 'yellow': 4, 'red': 2, 'fdw': 16, 'ped': 'fdw', 'ped_elapsed': 16, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'red', 'elapsed': 18, 'min_green': 20, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 17, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 14, 'min_green': 20, 'preempt_min_green': 5, 'yellow': 6, 'red': 3, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 19, 'preempt_min_green': 5, 'yellow': 3, 'red': 1, 'fdw': 14, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 9, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 4, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 10, 'yellow': 4, 'red': 3, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [3, 0])], [({'state': 'green', 'elapsed': 7, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 6, 'red': 3, 'fdw': 10, 'ped': 'walk', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'green', 'elapsed': 3, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 3, 'red': 3, 'fdw': 11, 'ped': 'fdw', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 13, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 4, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 13, 'min_green': 17, 'preempt_min_green': 7, 'yellow': 6, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 15, 'ped': 'walk', 'ped_elapsed': 4, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 20, 'min_green': 11, 'preempt_min_green': 9, 'yellow': 5, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 14, 'ped_truncate': False, 'track_current': True}, [0, 0])], [({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 1, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [1, 0]), ({'state': 'green', 'elapsed': 19, 'min_green': 9, 'preempt_min_green': 8, 'yellow': 3, 'red': 1, 'fdw': 24, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 11, 'preempt_min_green': 9, 'yellow': 4, 'red': 1, 'fdw': 14, 'ped': 'walk', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [19, 14]), ({'state': 'yellow', 'elapsed': 13, 'min_green': 15, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 5, 'red': 3, 'fdw': 9, 'ped': 'fdw', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': False}, [11, 3]), ({'state': 'green', 'elapsed': 0, 'min_green': 12, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 8, 'ped': 'fdw', 'ped_elapsed': 20, 'ped_truncate': True, 'track_current': False}, [10, 4])]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('timing oracle' + ' %d' % i, 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
timing oracle 0	`[22, 14]`	`[15, 7]`	Failed
timing oracle 1	`[4, 0]`	`[4, 0]`	Passed
timing oracle 2	`[0, 0]`	`[0, 0]`	Passed
timing oracle 3	`[8, 0]`	`[8, 0]`	Passed
timing oracle 4	`[20, 14]`	`[14, 8]`	Failed
timing oracle 5	`[9, 3]`	`[6, 0]`	Failed
timing oracle 6	`[2, 0]`	`[2, 0]`	Passed
timing oracle 7	`[0, 0]`	`[0, 0]`	Passed

SHA-256 / f6ccb1a4139c26fab52d9a3203255cbd5ff98d63a32b0ebce6d08245cd7a52dc

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(x):
    st, el = x['state'], x['elapsed']
    y, r, f = x['yellow'], x['red'], x['fdw']
    if st == 'green' and x['track_current']:
        return [0, 0]
    if st == 'red':
        return [max(0, r - el), 0]
    if st == 'yellow':
        return [max(0, y - el) + r, 0]
    ped = 0
    if x['ped'] == 'walk':
        ped = 0 if x['ped_truncate'] else f
    elif x['ped'] == 'fdw':
        ped = 0 if x['ped_truncate'] else max(0, f - x['ped_elapsed'])
    hold = max(ped, max(0, x['preempt_min_green']))
    return [hold + y + r, hold]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'state': 'green', 'elapsed': 2, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 6, 'red': 2, 'fdw': 11, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [15, 7]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 3, 'min_green': 8, 'preempt_min_green': 4, 'yellow': 6, 'red': 2, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'green', 'elapsed': 19, 'min_green': 19, 'preempt_min_green': 7, 'yellow': 6, 'red': 2, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [8, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 14, 'min_green': 17, 'preempt_min_green': 4, 'yellow': 3, 'red': 3, 'fdw': 22, 'ped': 'walk', 'ped_elapsed': 10, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 12, 'preempt_min_green': 4, 'yellow': 3, 'red': 1, 'fdw': 20, 'ped': 'none', 'ped_elapsed': 15, 'ped_truncate': True, 'track_current': False}, [2, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 9, 'preempt_min_green': 4, 'yellow': 4, 'red': 3, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 6, 'ped_truncate': False, 'track_current': False}, [0, 0])], [({'state': 'green', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 7, 'yellow': 3, 'red': 2, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [30, 25]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'yellow', 'elapsed': 6, 'min_green': 10, 'preempt_min_green': 2, 'yellow': 6, 'red': 3, 'fdw': 18, 'ped': 'none', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [3, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 7, 'min_green': 13, 'preempt_min_green': 3, 'yellow': 4, 'red': 1, 'fdw': 17, 'ped': 'walk', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [5, 0]), ({'state': 'green', 'elapsed': 14, 'min_green': 19, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 16, 'ped': 'walk', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [22, 16]), ({'state': 'green', 'elapsed': 0, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 5, 'red': 2, 'fdw': 21, 'ped': 'fdw', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [16, 9]), ({'state': 'green', 'elapsed': 19, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 2, 'fdw': 25, 'ped': 'walk', 'ped_elapsed': 11, 'ped_truncate': True, 'track_current': False}, [6, 0])], [({'state': 'green', 'elapsed': 14, 'min_green': 10, 'preempt_min_green': 9, 'yellow': 4, 'red': 2, 'fdw': 16, 'ped': 'fdw', 'ped_elapsed': 16, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'red', 'elapsed': 18, 'min_green': 20, 'preempt_min_green': 3, 'yellow': 5, 'red': 3, 'fdw': 17, 'ped': 'none', 'ped_elapsed': 13, 'ped_truncate': True, 'track_current': False}, [0, 0]), ({'state': 'red', 'elapsed': 14, 'min_green': 20, 'preempt_min_green': 5, 'yellow': 6, 'red': 3, 'fdw': 23, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': False}, [0, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 19, 'preempt_min_green': 5, 'yellow': 3, 'red': 1, 'fdw': 14, 'ped': 'walk', 'ped_elapsed': 0, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 9, 'min_green': 18, 'preempt_min_green': 9, 'yellow': 4, 'red': 2, 'fdw': 13, 'ped': 'none', 'ped_elapsed': 12, 'ped_truncate': False, 'track_current': False}, [6, 0]), ({'state': 'yellow', 'elapsed': 16, 'min_green': 16, 'preempt_min_green': 10, 'yellow': 4, 'red': 3, 'fdw': 10, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': False, 'track_current': False}, [3, 0])], [({'state': 'green', 'elapsed': 7, 'min_green': 16, 'preempt_min_green': 4, 'yellow': 6, 'red': 3, 'fdw': 10, 'ped': 'walk', 'ped_elapsed': 17, 'ped_truncate': False, 'track_current': True}, [0, 0]), ({'state': 'green', 'elapsed': 3, 'min_green': 16, 'preempt_min_green': 8, 'yellow': 3, 'red': 3, 'fdw': 11, 'ped': 'fdw', 'ped_elapsed': 17, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'red', 'elapsed': 11, 'min_green': 13, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 11, 'ped': 'none', 'ped_elapsed': 4, 'ped_truncate': True, 'track_current': True}, [0, 0]), ({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'green', 'elapsed': 13, 'min_green': 17, 'preempt_min_green': 7, 'yellow': 6, 'red': 3, 'fdw': 21, 'ped': 'none', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [9, 0]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'green', 'elapsed': 12, 'min_green': 20, 'preempt_min_green': 9, 'yellow': 5, 'red': 1, 'fdw': 15, 'ped': 'walk', 'ped_elapsed': 4, 'ped_truncate': True, 'track_current': False}, [6, 0]), ({'state': 'green', 'elapsed': 20, 'min_green': 11, 'preempt_min_green': 9, 'yellow': 5, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 14, 'ped_truncate': False, 'track_current': True}, [0, 0])], [({'state': 'green', 'elapsed': 1, 'min_green': 15, 'preempt_min_green': 5, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': False, 'track_current': False}, [14, 8]), ({'state': 'yellow', 'elapsed': 2, 'min_green': 10, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 12, 'ped': 'none', 'ped_elapsed': 0, 'ped_truncate': False, 'track_current': True}, [4, 0]), ({'state': 'yellow', 'elapsed': 12, 'min_green': 12, 'preempt_min_green': 3, 'yellow': 4, 'red': 1, 'fdw': 25, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': False}, [1, 0]), ({'state': 'green', 'elapsed': 19, 'min_green': 9, 'preempt_min_green': 8, 'yellow': 3, 'red': 1, 'fdw': 24, 'ped': 'fdw', 'ped_elapsed': 4, 'ped_truncate': True, 'track_current': False}, [4, 0]), ({'state': 'green', 'elapsed': 10, 'min_green': 11, 'preempt_min_green': 9, 'yellow': 4, 'red': 1, 'fdw': 14, 'ped': 'walk', 'ped_elapsed': 10, 'ped_truncate': False, 'track_current': False}, [19, 14]), ({'state': 'yellow', 'elapsed': 13, 'min_green': 15, 'preempt_min_green': 2, 'yellow': 3, 'red': 1, 'fdw': 19, 'ped': 'none', 'ped_elapsed': 19, 'ped_truncate': True, 'track_current': True}, [1, 0]), ({'state': 'green', 'elapsed': 6, 'min_green': 14, 'preempt_min_green': 9, 'yellow': 5, 'red': 3, 'fdw': 9, 'ped': 'fdw', 'ped_elapsed': 7, 'ped_truncate': False, 'track_current': False}, [11, 3]), ({'state': 'green', 'elapsed': 0, 'min_green': 12, 'preempt_min_green': 4, 'yellow': 4, 'red': 2, 'fdw': 8, 'ped': 'fdw', 'ped_elapsed': 20, 'ped_truncate': True, 'track_current': False}, [10, 4])]]
for i, (args, expected) in enumerate(fixtures[N-1]):
    check('timing oracle' + ' %d' % i, 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
timing oracle 0	`[16, 8]`	`[15, 7]`	Failed
timing oracle 1	`[4, 0]`	`[4, 0]`	Passed
timing oracle 2	`[0, 0]`	`[0, 0]`	Passed
timing oracle 3	`[15, 7]`	`[8, 0]`	Failed
timing oracle 4	`[14, 8]`	`[14, 8]`	Passed
timing oracle 5	`[10, 4]`	`[6, 0]`	Failed
timing oracle 6	`[2, 0]`	`[2, 0]`	Passed
timing oracle 7	`[0, 0]`	`[0, 0]`	Passed

SHA-256 / ab8f7b337bbe573824d8f55877cb0afeb0b927f79c5440d7e232830fb85a83d3

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.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

A deterministic, bounded toy model with a stipulated contract; it makes no claim of conformance to any agency manual or standard. 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 2026-09-29T14:47:59.629638+00:00.

Case digest / 1c98ceee41cd0661658f85f3be524b9572a9602ea063e32fc59080e6fdb00004