FA-68311 / Traffic signal timing plans / Open access

Conflict monitor fault scan: each live channel is paired with itself · case 01

Conflict monitor fault scan returns a wrong result when each live channel is paired with itself.

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

ROOT CAUSE

Adjacent live channels are never compared, hiding conflicts between neighbouring channel numbers.

VERIFIED REPAIR

Restore the pair enumeration rule so that the step reads `range(i + 1, len(live))`.

Unsuccessful approach: Starting at i pairs every channel with itself and reports self-conflicts.

Case contract

Input {channels: [[channel, lit colors string over R/Y/G, enabled]], compat: unordered compatible pairs, yellow_durations: [[channel, tenths]]}. Disabled channels are ignored entirely. A channel with more than one lit color is 'multi'; with none lit is 'red-fail'; any channel showing G or Y takes part in the conflict check, and every live pair not listed as compatible is 'conflict:a-b' (a<b). A completed yellow shorter than 2.7 s is 'short-yellow'. Return the sorted fault strings.

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):
    ok = {(min(a, b), max(a, b)) for a, b in x['compat']}
    faults = []
    live = []
    for ch, col, en in x['channels']:
        if not en:
            continue
        if len(col) > 1:
            faults.append('multi:%d' % ch)
        if col == '':
            faults.append('red-fail:%d' % ch)
        if 'G' in col or 'Y' in col:
            live.append(ch)
    live.sort()
    for i in range(len(live)):
        for j in range(i + 2, len(live)):
            if (live[i], live[j]) not in ok:
                faults.append('conflict:%d-%d' % (live[i], live[j]))
    for ch, tenths in x['yellow_durations']:
        if tenths < 27:
            faults.append('short-yellow:%d' % ch)
    return sorted(faults)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'RG', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 25]]}, ['short-yellow:2']), ({'channels': [[1, 'RG', False], [2, 'RY', False], [3, 'R', True], [4, 'R', True]], 'compat': [[3, 1], [1, 4], [4, 3]], 'yellow_durations': []}, []), ({'channels': [[1, 'GY', True], [2, 'R', False], [3, 'RG', True], [4, 'R', True], [5, 'RG', True]], 'compat': [[2, 1], [2, 4], [5, 2], [3, 4]], 'yellow_durations': [[4, 28], [5, 27]]}, ['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']), ({'channels': [[1, 'R', True], [2, '', True], [3, 'RG', False], [4, 'R', True], [5, '', True], [6, 'R', True]], 'compat': [[1, 2], [1, 6], [2, 3], [4, 2], [6, 2], [3, 5], [4, 6], [6, 5]], 'yellow_durations': [[1, 25], [3, 26]]}, ['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'RG', True], [2, 'G', True], [3, 'GY', True], [4, 'RG', True]], 'compat': [[1, 4], [2, 4], [3, 4]], 'yellow_durations': [[3, 25], [4, 28]]}, ['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']), ({'channels': [[1, 'R', False], [2, 'GY', False], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 25]]}, ['red-fail:3', 'short-yellow:1'])], [({'channels': [[1, 'RY', False], [2, 'R', True], [3, '', True]], 'compat': [[2, 1]], 'yellow_durations': [[2, 25]]}, ['red-fail:3', 'short-yellow:2']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'RG', False], [5, '', True]], 'compat': [[1, 2], [1, 4], [2, 3], [2, 5], [3, 5]], 'yellow_durations': [[1, 26], [3, 28], [5, 27]]}, ['red-fail:5', 'short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'R', True], [2, 'R', False], [3, '', False]], 'compat': [[1, 2]], 'yellow_durations': [[1, 30]]}, []), ({'channels': [[1, 'R', True], [2, 'G', True], [3, 'Y', True], [4, 'R', True], [5, 'RG', True]], 'compat': [[2, 3], [2, 5], [4, 5]], 'yellow_durations': [[2, 27], [3, 28]]}, ['conflict:3-5', 'multi:5']), ({'channels': [[1, 'R', False], [2, 'R', True], [3, 'R', True]], 'compat': [], 'yellow_durations': []}, []), ({'channels': [[1, 'GY', True], [2, 'R', False], [3, 'R', True], [4, 'R', True], [5, 'GY', True], [6, 'R', True]], 'compat': [[2, 1], [4, 2], [5, 2], [6, 2], [4, 6], [5, 6]], 'yellow_durations': []}, ['conflict:1-5', 'multi:1', 'multi:5'])], [({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', False]], 'compat': [[2, 1]], 'yellow_durations': [[1, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', False], [3, '', True], [4, 'R', True]], 'compat': [[2, 1], [4, 1], [2, 3], [4, 2]], 'yellow_durations': [[1, 27], [3, 25], [4, 27]]}, ['red-fail:3', 'short-yellow:3']), ({'channels': [[1, 'Y', True], [2, 'RY', True], [3, 'R', True], [4, 'R', True], [5, 'R', True]], 'compat': [[5, 2], [3, 5]], 'yellow_durations': [[1, 35], [5, 35]]}, ['conflict:1-2', 'multi:2']), ({'channels': [[1, 'GY', True], [2, 'GY', True], [3, 'R', True]], 'compat': [], 'yellow_durations': []}, ['conflict:1-2', 'multi:1', 'multi:2']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', False]], 'compat': [], 'yellow_durations': [[2, 35]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'GY', False], [2, 'R', False], [3, '', True]], 'compat': [[3, 2]], 'yellow_durations': [[1, 27], [3, 25]]}, ['red-fail:3', 'short-yellow:3'])], [({'channels': [[1, 'R', True], [2, 'R', True], [3, '', False], [4, 'R', True], [5, 'R', True], [6, 'RY', False]], 'compat': [[4, 1], [5, 1], [5, 2], [2, 6], [5, 4], [4, 6]], 'yellow_durations': []}, []), ({'channels': [[1, 'Y', True], [2, 'R', True], [3, 'GY', True], [4, 'RY', True], [5, 'R', True]], 'compat': [[2, 1], [4, 5]], 'yellow_durations': [[4, 30], [5, 26]]}, ['conflict:1-3', 'conflict:1-4', 'conflict:3-4', 'multi:3', 'multi:4', 'short-yellow:5']), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, '', False], [3, 'R', False], [4, 'R', True]], 'compat': [[2, 1], [2, 3], [4, 3]], 'yellow_durations': [[2, 25]]}, ['short-yellow:2']), ({'channels': [[1, '', True], [2, 'R', True], [3, 'R', True]], 'compat': [[1, 2]], 'yellow_durations': [[2, 28]]}, ['red-fail:1']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'Y', True], [5, 'R', False], [6, 'RY', True]], 'compat': [[1, 3], [1, 5], [2, 3], [6, 2], [4, 3]], 'yellow_durations': [[2, 27], [3, 28], [5, 26], [6, 25]]}, ['conflict:4-6', 'multi:6', 'short-yellow:5', 'short-yellow:6']), ({'channels': [[1, '', True], [2, 'R', True], [3, '', True], [4, 'R', True], [5, 'R', True]], 'compat': [[1, 2], [3, 1], [1, 4], [4, 2], [5, 3]], 'yellow_durations': []}, ['red-fail:1', 'red-fail:3'])], [({'channels': [[1, '', True], [2, 'R', False], [3, 'R', True]], 'compat': [[2, 3]], 'yellow_durations': []}, ['red-fail:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, '', True], [2, 'RG', True], [3, 'Y', True], [4, 'R', True], [5, 'R', False]], 'compat': [[5, 4]], 'yellow_durations': [[3, 35]]}, ['conflict:2-3', 'multi:2', 'red-fail:1']), ({'channels': [[1, '', True], [2, '', True], [3, 'R', True]], 'compat': [[3, 1]], 'yellow_durations': []}, ['red-fail:1', 'red-fail:2']), ({'channels': [[1, 'G', False], [2, '', True], [3, '', False], [4, 'Y', False]], 'compat': [[1, 4], [3, 2], [4, 2]], 'yellow_durations': [[1, 26], [3, 27]]}, ['red-fail:2', 'short-yellow:1']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'R', True]], 'compat': [[3, 1], [1, 4], [4, 2]], 'yellow_durations': [[1, 25], [2, 28]]}, ['short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'Y', True], [3, 'RY', True], [4, 'R', True]], 'compat': [[1, 4], [2, 3]], 'yellow_durations': [[1, 35]]}, ['conflict:1-2', 'conflict:1-3', 'multi:3'])]]
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	`[]`	`[]`	Passed
timing oracle 1	`['short-yellow:2']`	`['short-yellow:2']`	Passed
timing oracle 2	`[]`	`[]`	Passed
timing oracle 3	`['conflict:1-5', 'multi:1', 'multi:3', 'multi:5']`	`['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']`	Failed
timing oracle 4	`['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']`	`['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']`	Passed
timing oracle 5	`['multi:1', 'red-fail:3', 'short-yellow:1']`	`['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']`	Failed
timing oracle 6	`['conflict:1-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']`	`['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']`	Failed
timing oracle 7	`['red-fail:3', 'short-yellow:1']`	`['red-fail:3', 'short-yellow:1']`	Passed

SHA-256 / d1d95707691f67a663c4513d13cb875d93cbbef417af0ec6bf3bf81467ea27c0

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(x):
    ok = {(min(a, b), max(a, b)) for a, b in x['compat']}
    faults = []
    live = []
    for ch, col, en in x['channels']:
        if not en:
            continue
        if len(col) > 1:
            faults.append('multi:%d' % ch)
        if col == '':
            faults.append('red-fail:%d' % ch)
        if 'G' in col or 'Y' in col:
            live.append(ch)
    live.sort()
    for i in range(len(live)):
        for j in range(i, len(live)):
            if (live[i], live[j]) not in ok:
                faults.append('conflict:%d-%d' % (live[i], live[j]))
    for ch, tenths in x['yellow_durations']:
        if tenths < 27:
            faults.append('short-yellow:%d' % ch)
    return sorted(faults)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'RG', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 25]]}, ['short-yellow:2']), ({'channels': [[1, 'RG', False], [2, 'RY', False], [3, 'R', True], [4, 'R', True]], 'compat': [[3, 1], [1, 4], [4, 3]], 'yellow_durations': []}, []), ({'channels': [[1, 'GY', True], [2, 'R', False], [3, 'RG', True], [4, 'R', True], [5, 'RG', True]], 'compat': [[2, 1], [2, 4], [5, 2], [3, 4]], 'yellow_durations': [[4, 28], [5, 27]]}, ['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']), ({'channels': [[1, 'R', True], [2, '', True], [3, 'RG', False], [4, 'R', True], [5, '', True], [6, 'R', True]], 'compat': [[1, 2], [1, 6], [2, 3], [4, 2], [6, 2], [3, 5], [4, 6], [6, 5]], 'yellow_durations': [[1, 25], [3, 26]]}, ['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'RG', True], [2, 'G', True], [3, 'GY', True], [4, 'RG', True]], 'compat': [[1, 4], [2, 4], [3, 4]], 'yellow_durations': [[3, 25], [4, 28]]}, ['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']), ({'channels': [[1, 'R', False], [2, 'GY', False], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 25]]}, ['red-fail:3', 'short-yellow:1'])], [({'channels': [[1, 'RY', False], [2, 'R', True], [3, '', True]], 'compat': [[2, 1]], 'yellow_durations': [[2, 25]]}, ['red-fail:3', 'short-yellow:2']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'RG', False], [5, '', True]], 'compat': [[1, 2], [1, 4], [2, 3], [2, 5], [3, 5]], 'yellow_durations': [[1, 26], [3, 28], [5, 27]]}, ['red-fail:5', 'short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'R', True], [2, 'R', False], [3, '', False]], 'compat': [[1, 2]], 'yellow_durations': [[1, 30]]}, []), ({'channels': [[1, 'R', True], [2, 'G', True], [3, 'Y', True], [4, 'R', True], [5, 'RG', True]], 'compat': [[2, 3], [2, 5], [4, 5]], 'yellow_durations': [[2, 27], [3, 28]]}, ['conflict:3-5', 'multi:5']), ({'channels': [[1, 'R', False], [2, 'R', True], [3, 'R', True]], 'compat': [], 'yellow_durations': []}, []), ({'channels': [[1, 'GY', True], [2, 'R', False], [3, 'R', True], [4, 'R', True], [5, 'GY', True], [6, 'R', True]], 'compat': [[2, 1], [4, 2], [5, 2], [6, 2], [4, 6], [5, 6]], 'yellow_durations': []}, ['conflict:1-5', 'multi:1', 'multi:5'])], [({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', False]], 'compat': [[2, 1]], 'yellow_durations': [[1, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', False], [3, '', True], [4, 'R', True]], 'compat': [[2, 1], [4, 1], [2, 3], [4, 2]], 'yellow_durations': [[1, 27], [3, 25], [4, 27]]}, ['red-fail:3', 'short-yellow:3']), ({'channels': [[1, 'Y', True], [2, 'RY', True], [3, 'R', True], [4, 'R', True], [5, 'R', True]], 'compat': [[5, 2], [3, 5]], 'yellow_durations': [[1, 35], [5, 35]]}, ['conflict:1-2', 'multi:2']), ({'channels': [[1, 'GY', True], [2, 'GY', True], [3, 'R', True]], 'compat': [], 'yellow_durations': []}, ['conflict:1-2', 'multi:1', 'multi:2']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', False]], 'compat': [], 'yellow_durations': [[2, 35]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'GY', False], [2, 'R', False], [3, '', True]], 'compat': [[3, 2]], 'yellow_durations': [[1, 27], [3, 25]]}, ['red-fail:3', 'short-yellow:3'])], [({'channels': [[1, 'R', True], [2, 'R', True], [3, '', False], [4, 'R', True], [5, 'R', True], [6, 'RY', False]], 'compat': [[4, 1], [5, 1], [5, 2], [2, 6], [5, 4], [4, 6]], 'yellow_durations': []}, []), ({'channels': [[1, 'Y', True], [2, 'R', True], [3, 'GY', True], [4, 'RY', True], [5, 'R', True]], 'compat': [[2, 1], [4, 5]], 'yellow_durations': [[4, 30], [5, 26]]}, ['conflict:1-3', 'conflict:1-4', 'conflict:3-4', 'multi:3', 'multi:4', 'short-yellow:5']), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, '', False], [3, 'R', False], [4, 'R', True]], 'compat': [[2, 1], [2, 3], [4, 3]], 'yellow_durations': [[2, 25]]}, ['short-yellow:2']), ({'channels': [[1, '', True], [2, 'R', True], [3, 'R', True]], 'compat': [[1, 2]], 'yellow_durations': [[2, 28]]}, ['red-fail:1']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'Y', True], [5, 'R', False], [6, 'RY', True]], 'compat': [[1, 3], [1, 5], [2, 3], [6, 2], [4, 3]], 'yellow_durations': [[2, 27], [3, 28], [5, 26], [6, 25]]}, ['conflict:4-6', 'multi:6', 'short-yellow:5', 'short-yellow:6']), ({'channels': [[1, '', True], [2, 'R', True], [3, '', True], [4, 'R', True], [5, 'R', True]], 'compat': [[1, 2], [3, 1], [1, 4], [4, 2], [5, 3]], 'yellow_durations': []}, ['red-fail:1', 'red-fail:3'])], [({'channels': [[1, '', True], [2, 'R', False], [3, 'R', True]], 'compat': [[2, 3]], 'yellow_durations': []}, ['red-fail:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, '', True], [2, 'RG', True], [3, 'Y', True], [4, 'R', True], [5, 'R', False]], 'compat': [[5, 4]], 'yellow_durations': [[3, 35]]}, ['conflict:2-3', 'multi:2', 'red-fail:1']), ({'channels': [[1, '', True], [2, '', True], [3, 'R', True]], 'compat': [[3, 1]], 'yellow_durations': []}, ['red-fail:1', 'red-fail:2']), ({'channels': [[1, 'G', False], [2, '', True], [3, '', False], [4, 'Y', False]], 'compat': [[1, 4], [3, 2], [4, 2]], 'yellow_durations': [[1, 26], [3, 27]]}, ['red-fail:2', 'short-yellow:1']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'R', True]], 'compat': [[3, 1], [1, 4], [4, 2]], 'yellow_durations': [[1, 25], [2, 28]]}, ['short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'Y', True], [3, 'RY', True], [4, 'R', True]], 'compat': [[1, 4], [2, 3]], 'yellow_durations': [[1, 35]]}, ['conflict:1-2', 'conflict:1-3', 'multi:3'])]]
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	`['conflict:1-1', 'conflict:3-3']`	`[]`	Failed
timing oracle 1	`['short-yellow:2']`	`['short-yellow:2']`	Passed
timing oracle 2	`[]`	`[]`	Passed
timing oracle 3	`['conflict:1-1', 'conflict:1-3', 'conflict:1-5', 'conflict:3-3', 'conflict:3-5', 'conflict:5-5', 'multi:1', 'multi:3', 'multi:5']`	`['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']`	Failed
timing oracle 4	`['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']`	`['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']`	Passed
timing oracle 5	`['conflict:1-1', 'conflict:1-2', 'conflict:2-2', 'multi:1', 'red-fail:3', 'short-yellow:1']`	`['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']`	Failed
timing oracle 6	`['conflict:1-1', 'conflict:1-2', 'conflict:1-3', 'conflict:2-2', 'conflict:2-3', 'conflict:3-3', 'conflict:4-4', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']`	`['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']`	Failed
timing oracle 7	`['red-fail:3', 'short-yellow:1']`	`['red-fail:3', 'short-yellow:1']`	Passed

SHA-256 / 274023b0b6488aa0a133e4b1aa971f9647499b6406e47ce09a7be7dea89827bc

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(x):
    ok = {(min(a, b), max(a, b)) for a, b in x['compat']}
    faults = []
    live = []
    for ch, col, en in x['channels']:
        if not en:
            continue
        if len(col) > 1:
            faults.append('multi:%d' % ch)
        if col == '':
            faults.append('red-fail:%d' % ch)
        if 'G' in col or 'Y' in col:
            live.append(ch)
    live.sort()
    for i in range(len(live)):
        for j in range(i + 1, len(live)):
            if (live[i], live[j]) not in ok:
                faults.append('conflict:%d-%d' % (live[i], live[j]))
    for ch, tenths in x['yellow_durations']:
        if tenths < 27:
            faults.append('short-yellow:%d' % ch)
    return sorted(faults)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'RG', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 25]]}, ['short-yellow:2']), ({'channels': [[1, 'RG', False], [2, 'RY', False], [3, 'R', True], [4, 'R', True]], 'compat': [[3, 1], [1, 4], [4, 3]], 'yellow_durations': []}, []), ({'channels': [[1, 'GY', True], [2, 'R', False], [3, 'RG', True], [4, 'R', True], [5, 'RG', True]], 'compat': [[2, 1], [2, 4], [5, 2], [3, 4]], 'yellow_durations': [[4, 28], [5, 27]]}, ['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']), ({'channels': [[1, 'R', True], [2, '', True], [3, 'RG', False], [4, 'R', True], [5, '', True], [6, 'R', True]], 'compat': [[1, 2], [1, 6], [2, 3], [4, 2], [6, 2], [3, 5], [4, 6], [6, 5]], 'yellow_durations': [[1, 25], [3, 26]]}, ['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'RG', True], [2, 'G', True], [3, 'GY', True], [4, 'RG', True]], 'compat': [[1, 4], [2, 4], [3, 4]], 'yellow_durations': [[3, 25], [4, 28]]}, ['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']), ({'channels': [[1, 'R', False], [2, 'GY', False], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 25]]}, ['red-fail:3', 'short-yellow:1'])], [({'channels': [[1, 'RY', False], [2, 'R', True], [3, '', True]], 'compat': [[2, 1]], 'yellow_durations': [[2, 25]]}, ['red-fail:3', 'short-yellow:2']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'RG', False], [5, '', True]], 'compat': [[1, 2], [1, 4], [2, 3], [2, 5], [3, 5]], 'yellow_durations': [[1, 26], [3, 28], [5, 27]]}, ['red-fail:5', 'short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'R', True], [2, 'R', False], [3, '', False]], 'compat': [[1, 2]], 'yellow_durations': [[1, 30]]}, []), ({'channels': [[1, 'R', True], [2, 'G', True], [3, 'Y', True], [4, 'R', True], [5, 'RG', True]], 'compat': [[2, 3], [2, 5], [4, 5]], 'yellow_durations': [[2, 27], [3, 28]]}, ['conflict:3-5', 'multi:5']), ({'channels': [[1, 'R', False], [2, 'R', True], [3, 'R', True]], 'compat': [], 'yellow_durations': []}, []), ({'channels': [[1, 'GY', True], [2, 'R', False], [3, 'R', True], [4, 'R', True], [5, 'GY', True], [6, 'R', True]], 'compat': [[2, 1], [4, 2], [5, 2], [6, 2], [4, 6], [5, 6]], 'yellow_durations': []}, ['conflict:1-5', 'multi:1', 'multi:5'])], [({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', False]], 'compat': [[2, 1]], 'yellow_durations': [[1, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', False], [3, '', True], [4, 'R', True]], 'compat': [[2, 1], [4, 1], [2, 3], [4, 2]], 'yellow_durations': [[1, 27], [3, 25], [4, 27]]}, ['red-fail:3', 'short-yellow:3']), ({'channels': [[1, 'Y', True], [2, 'RY', True], [3, 'R', True], [4, 'R', True], [5, 'R', True]], 'compat': [[5, 2], [3, 5]], 'yellow_durations': [[1, 35], [5, 35]]}, ['conflict:1-2', 'multi:2']), ({'channels': [[1, 'GY', True], [2, 'GY', True], [3, 'R', True]], 'compat': [], 'yellow_durations': []}, ['conflict:1-2', 'multi:1', 'multi:2']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', False]], 'compat': [], 'yellow_durations': [[2, 35]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'GY', False], [2, 'R', False], [3, '', True]], 'compat': [[3, 2]], 'yellow_durations': [[1, 27], [3, 25]]}, ['red-fail:3', 'short-yellow:3'])], [({'channels': [[1, 'R', True], [2, 'R', True], [3, '', False], [4, 'R', True], [5, 'R', True], [6, 'RY', False]], 'compat': [[4, 1], [5, 1], [5, 2], [2, 6], [5, 4], [4, 6]], 'yellow_durations': []}, []), ({'channels': [[1, 'Y', True], [2, 'R', True], [3, 'GY', True], [4, 'RY', True], [5, 'R', True]], 'compat': [[2, 1], [4, 5]], 'yellow_durations': [[4, 30], [5, 26]]}, ['conflict:1-3', 'conflict:1-4', 'conflict:3-4', 'multi:3', 'multi:4', 'short-yellow:5']), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'R', True], [2, '', False], [3, 'R', False], [4, 'R', True]], 'compat': [[2, 1], [2, 3], [4, 3]], 'yellow_durations': [[2, 25]]}, ['short-yellow:2']), ({'channels': [[1, '', True], [2, 'R', True], [3, 'R', True]], 'compat': [[1, 2]], 'yellow_durations': [[2, 28]]}, ['red-fail:1']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'Y', True], [5, 'R', False], [6, 'RY', True]], 'compat': [[1, 3], [1, 5], [2, 3], [6, 2], [4, 3]], 'yellow_durations': [[2, 27], [3, 28], [5, 26], [6, 25]]}, ['conflict:4-6', 'multi:6', 'short-yellow:5', 'short-yellow:6']), ({'channels': [[1, '', True], [2, 'R', True], [3, '', True], [4, 'R', True], [5, 'R', True]], 'compat': [[1, 2], [3, 1], [1, 4], [4, 2], [5, 3]], 'yellow_durations': []}, ['red-fail:1', 'red-fail:3'])], [({'channels': [[1, '', True], [2, 'R', False], [3, 'R', True]], 'compat': [[2, 3]], 'yellow_durations': []}, ['red-fail:1']), ({'channels': [[1, 'G', True], [2, 'R', True], [3, 'Y', True], [4, 'G', False]], 'compat': [[3, 1]], 'yellow_durations': [[2, 27]]}, []), ({'channels': [[1, 'GY', True], [2, 'G', True], [3, '', True]], 'compat': [], 'yellow_durations': [[1, 26]]}, ['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']), ({'channels': [[1, '', True], [2, 'RG', True], [3, 'Y', True], [4, 'R', True], [5, 'R', False]], 'compat': [[5, 4]], 'yellow_durations': [[3, 35]]}, ['conflict:2-3', 'multi:2', 'red-fail:1']), ({'channels': [[1, '', True], [2, '', True], [3, 'R', True]], 'compat': [[3, 1]], 'yellow_durations': []}, ['red-fail:1', 'red-fail:2']), ({'channels': [[1, 'G', False], [2, '', True], [3, '', False], [4, 'Y', False]], 'compat': [[1, 4], [3, 2], [4, 2]], 'yellow_durations': [[1, 26], [3, 27]]}, ['red-fail:2', 'short-yellow:1']), ({'channels': [[1, 'R', True], [2, 'R', True], [3, 'R', True], [4, 'R', True]], 'compat': [[3, 1], [1, 4], [4, 2]], 'yellow_durations': [[1, 25], [2, 28]]}, ['short-yellow:1']), ({'channels': [[1, 'G', True], [2, 'Y', True], [3, 'RY', True], [4, 'R', True]], 'compat': [[1, 4], [2, 3]], 'yellow_durations': [[1, 35]]}, ['conflict:1-2', 'conflict:1-3', 'multi:3'])]]
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	`[]`	`[]`	Passed
timing oracle 1	`['short-yellow:2']`	`['short-yellow:2']`	Passed
timing oracle 2	`[]`	`[]`	Passed
timing oracle 3	`['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']`	`['conflict:1-3', 'conflict:1-5', 'conflict:3-5', 'multi:1', 'multi:3', 'multi:5']`	Passed
timing oracle 4	`['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']`	`['red-fail:2', 'red-fail:5', 'short-yellow:1', 'short-yellow:3']`	Passed
timing oracle 5	`['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']`	`['conflict:1-2', 'multi:1', 'red-fail:3', 'short-yellow:1']`	Passed
timing oracle 6	`['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']`	`['conflict:1-2', 'conflict:1-3', 'conflict:2-3', 'multi:1', 'multi:3', 'multi:4', 'short-yellow:3']`	Passed
timing oracle 7	`['red-fail:3', 'short-yellow:1']`	`['red-fail:3', 'short-yellow:1']`	Passed

SHA-256 / 1de8ce93ce0bd719683f12417b63782522b03551f52b202952cffef8676d53d3

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 2026-09-29T14:48:01.033644+00:00.

Case digest / f96aca2fd1be86e4d4eb70ef0ff5cb34d6b06a90bf300a0a195e4b4a9efe4604