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FA-38391 / Tree accessibility / Open access

Hierarchical checkbox cascade: Disabled descendants become writable · case 01

Disabled descendants become writable produces the wrong hierarchical widget state in a regression fixture.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The checkbox-cascade contract is violated at `if x not in disabled` by replacing it with `if x in disabled`.

THE FAILURE

The checkbox-cascade contract is violated at `if x not in disabled` by replacing it with `if x in disabled`.

Unsuccessful approach: The partial repair `if True` still violates a boundary or preservation case.

Case contract

Descendants and leaves are supplied for one branch, without cycles. Toggle writable leaves only. Preserve disabled and unrelated checks; derive parent state from writable leaves; unknown children force mixed unless no leaves are checked.

Why this case matters

Offline executable model of a hierarchical accessibility interaction; inputs are bounded and valid as stipulated. No browser, assistive technology, or normative ARIA conformance is claimed.

1 / The failure

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

N = 1
observations = []
def solve(d):
    leaves=d['leaves']; disabled=set(d['disabled']); checked=set(d['checked'])
    write=[x for x in leaves if x in disabled]
    target=not all(x in checked for x in write) if write else False
    keep=checked-set(write)
    changed=set(write) if target else set()
    after=keep|changed
    count=sum(x in after for x in write)
    complete=bool(write) and count==len(write) and not d['unknown']
    mixed=count>0 and not complete
    state='true' if complete else ('mixed' if mixed else 'false')
    order=[x for x in d['all'] if x in after]
    changed_ids=[x for x in write if (x in checked)!=(x in after)]
    return [order,state,changed_ids,target]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('partial', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2'], 'true', ['c2'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['c0', 'c2'], 'true', ['c0', 'c2'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2'], 'mixed', ['c2'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['c0', 'c1', 'c2'], 'true', ['c0', 'c2'], True])], 2: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3'], 'true', ['c2', 'c3'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['c0', 'c2', 'c3'], 'true', ['c0', 'c2', 'c3'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3'], 'mixed', ['c2', 'c3'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3'], 'true', ['c0', 'c2', 'c3'], True])], 3: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'true', ['c2', 'c3', 'c4'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3', 'c4'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['c0', 'c2', 'c3', 'c4'], 'true', ['c0', 'c2', 'c3', 'c4'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'mixed', ['c2', 'c3', 'c4'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3', 'c4'], 'true', ['c0', 'c2', 'c3', 'c4'], True])], 4: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'true', ['c2', 'c3', 'c4', 'c5'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3', 'c4', 'c5'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['c0', 'c2', 'c3', 'c4', 'c5'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'mixed', ['c2', 'c3', 'c4', 'c5'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5'], True])], 5: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'true', ['c2', 'c3', 'c4', 'c5', 'c6'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'mixed', ['c2', 'c3', 'c4', 'c5', 'c6'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], True])]}
for label, data, expected in cases[N]:
    check(label, solve(data), 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
partial[['outside', 'c0'], 'false', ['c1'], False][['outside', 'c0', 'c1', 'c2'], 'true', ['c2'], True]Failed
all checked[['outside', 'c0', 'c2'], 'false', ['c1'], False][['outside', 'c1'], 'false', ['c0', 'c2'], False]Failed
none checked[['c1'], 'true', ['c1'], True][['c0', 'c2'], 'true', ['c0', 'c2'], True]Failed
unknown descendants[['outside', 'c0'], 'false', ['c1'], False][['outside', 'c0', 'c1', 'c2'], 'mixed', ['c2'], True]Failed
empty branch[['outside', 'c0', 'c1'], 'false', [], False][['outside', 'c0', 'c1'], 'false', [], False]Passed
disabled only[['outside', 'c0'], 'false', ['c1'], False][['outside', 'c0', 'c1'], 'false', [], False]Failed
protected checked[[], 'false', ['c1'], False][['c0', 'c1', 'c2'], 'true', ['c0', 'c2'], True]Failed

SHA-256 / 6038c9b0b0f55b16721ed023d60a5d8f6d48ed851d72e538711379680e623e22

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(d):
    leaves=d['leaves']; disabled=set(d['disabled']); checked=set(d['checked'])
    write=[x for x in leaves if True]
    target=not all(x in checked for x in write) if write else False
    keep=checked-set(write)
    changed=set(write) if target else set()
    after=keep|changed
    count=sum(x in after for x in write)
    complete=bool(write) and count==len(write) and not d['unknown']
    mixed=count>0 and not complete
    state='true' if complete else ('mixed' if mixed else 'false')
    order=[x for x in d['all'] if x in after]
    changed_ids=[x for x in write if (x in checked)!=(x in after)]
    return [order,state,changed_ids,target]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = {1: [('partial', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2'], 'true', ['c2'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['c0', 'c2'], 'true', ['c0', 'c2'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2'], 'mixed', ['c2'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2'], 'unknown': False}, [['c0', 'c1', 'c2'], 'true', ['c0', 'c2'], True])], 2: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3'], 'true', ['c2', 'c3'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['c0', 'c2', 'c3'], 'true', ['c0', 'c2', 'c3'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3'], 'mixed', ['c2', 'c3'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3'], 'true', ['c0', 'c2', 'c3'], True])], 3: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'true', ['c2', 'c3', 'c4'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3', 'c4'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['c0', 'c2', 'c3', 'c4'], 'true', ['c0', 'c2', 'c3', 'c4'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'mixed', ['c2', 'c3', 'c4'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3', 'c4'], 'true', ['c0', 'c2', 'c3', 'c4'], True])], 4: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'true', ['c2', 'c3', 'c4', 'c5'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3', 'c4', 'c5'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['c0', 'c2', 'c3', 'c4', 'c5'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'mixed', ['c2', 'c3', 'c4', 'c5'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3', 'c4', 'c5'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5'], True])], 5: [('partial', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'true', ['c2', 'c3', 'c4', 'c5', 'c6'], True]), ('all checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c1'], 'false', ['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], False]), ('none checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': [], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], True]), ('unknown descendants', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': True}, [['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'mixed', ['c2', 'c3', 'c4', 'c5', 'c6'], True]), ('empty branch', {'leaves': [], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('disabled only', {'leaves': ['c1'], 'disabled': ['c1'], 'checked': ['outside', 'c0', 'c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['outside', 'c0', 'c1'], 'false', [], False]), ('protected checked', {'leaves': ['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'disabled': ['c1'], 'checked': ['c1'], 'all': ['outside', 'c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'unknown': False}, [['c0', 'c1', 'c2', 'c3', 'c4', 'c5', 'c6'], 'true', ['c0', 'c2', 'c3', 'c4', 'c5', 'c6'], True])]}
for label, data, expected in cases[N]:
    check(label, solve(data), 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
partial[['outside', 'c0', 'c1', 'c2'], 'true', ['c2'], True][['outside', 'c0', 'c1', 'c2'], 'true', ['c2'], True]Passed
all checked[['outside'], 'false', ['c0', 'c1', 'c2'], False][['outside', 'c1'], 'false', ['c0', 'c2'], False]Failed
none checked[['c0', 'c1', 'c2'], 'true', ['c0', 'c1', 'c2'], True][['c0', 'c2'], 'true', ['c0', 'c2'], True]Failed
unknown descendants[['outside', 'c0', 'c1', 'c2'], 'mixed', ['c2'], True][['outside', 'c0', 'c1', 'c2'], 'mixed', ['c2'], True]Passed
empty branch[['outside', 'c0', 'c1'], 'false', [], False][['outside', 'c0', 'c1'], 'false', [], False]Passed
disabled only[['outside', 'c0'], 'false', ['c1'], False][['outside', 'c0', 'c1'], 'false', [], False]Failed
protected checked[['c0', 'c1', 'c2'], 'true', ['c0', 'c2'], True][['c0', 'c1', 'c2'], 'true', ['c0', 'c2'], True]Passed

SHA-256 / 0f997c48a75db82cb3777cfb49937e2281d3f730cc6754e27bf8666a8d6ed883

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 7 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.

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Verification & scope

Synthetic deterministic hierarchical-widget data contract; not an implementation of a browser accessibility tree. 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 2026-09-29T14:43:11.150987+00:00.

Case digest / b3f4a8ae3a44a372f3a3257b0cc47ce6c647663e59d190ad5a9ae41f7dec1350