FAILURE MAP
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FA-54266 / Accessibility interaction semantics / Open access

Detail providers lose the inverse consumer relationship · case 01

Detail providers lose the inverse consumer relationship.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The details inverse decision in the inverse relations adapter violates its declared contract.

THE FAILURE

The details inverse decision in the inverse relations adapter violates its declared contract.

Unsuccessful approach: The local repair substitutes 'details':'described_by' but still mishandles the regression fixtures.

Case contract

Input [node_ids,relations] relations [source,kind,target]. Kind label_for maps inverse labelled_by, description_for maps described_by, controls maps controlled_by, details maps details_for. Unknown types ignored. Resolve only existing distinct nodes. For each node output direct and inverse [kind,other_id] pairs, deduping while preserving relation encounter order. Direct is appended before inverse. Nodes with no links are retained in input order; input node IDs are unique. Forward and reverse kinds remain distinct even for reciprocal declarations.

Why this case matters

Offline accessibility bridge model with explicit policy; useful for testing semantic API adapters independently of browser implementations.

1 / The failure

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

N = 1
observations = []
def solve(data):
    nodes,relations = data
    inverse = {'label_for':'labelled_by','description_for':'described_by','controls':'controlled_by','details':'details'}
    result = {node:[] for node in nodes}
    for source,kind,target in relations:
        if kind not in inverse or source not in result or target not in result or source == target: continue
        forward = [kind,target]
        backward = [inverse[kind],source]
        if forward not in result[source]: result[source].append(forward)
        if backward not in result[target]: result[target].append(backward)
    return [[node,result[node]] for node in nodes]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([['a','b',str(N),'alone'],[['a','label_for','b'],['a','description_for','b'],['b','controls',str(N)],['a','details',str(N)]]],), [['a',[['label_for','b'],['description_for','b'],['details',str(N)]]],['b',[['labelled_by','a'],['described_by','a'],['controls',str(N)]]],[str(N),[['controlled_by','b'],['details_for','a']]],['alone',[]]])
check('contract fixture 2', solve([['a','b'],[['a','controls','b'],['b','controls','a']]],), [['a',[['controls','b'],['controlled_by','b']]],['b',[['controlled_by','a'],['controls','a']]]])
check('contract fixture 3', solve([['a','b'],[['a','controls','b'],['a','controls','b']]],), [['a',[['controls','b']]],['b',[['controlled_by','a']]]])
check('contract fixture 4', solve([['a'],[['a','controls','a'],['a','unknown','a'],['a','controls','missing'],['missing','details','a']]],), [['a',[]]])
check('contract fixture 5', solve([['z','a'],[]],), [['z',[]],['a',[]]])
check('contract fixture 6', solve([[],[]],), [])
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
contract fixture 1[['a', [['label_for', 'b'], ['description_for', 'b'], ['details', '1']]], ['b', [['labelled_by', 'a'], ['described_by', 'a'], ['controls', '1']]], ['1', [['controlled_by', 'b'], ['details', 'a']]], ['alone', []]][['a', [['label_for', 'b'], ['description_for', 'b'], ['details', '1']]], ['b', [['labelled_by', 'a'], ['described_by', 'a'], ['controls', '1']]], ['1', [['controlled_by', 'b'], ['details_for', 'a']]], ['alone', []]]Failed
contract fixture 2[['a', [['controls', 'b'], ['controlled_by', 'b']]], ['b', [['controlled_by', 'a'], ['controls', 'a']]]][['a', [['controls', 'b'], ['controlled_by', 'b']]], ['b', [['controlled_by', 'a'], ['controls', 'a']]]]Passed
contract fixture 3[['a', [['controls', 'b']]], ['b', [['controlled_by', 'a']]]][['a', [['controls', 'b']]], ['b', [['controlled_by', 'a']]]]Passed
contract fixture 4[['a', []]][['a', []]]Passed
contract fixture 5[['z', []], ['a', []]][['z', []], ['a', []]]Passed
contract fixture 6[][]Passed

SHA-256 / 1396eb452ea4bf82c2dce97fc478a52e68c7cd80a5e25f8754a3f056ebff4f8e

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(data):
    nodes,relations = data
    inverse = {'label_for':'labelled_by','description_for':'described_by','controls':'controlled_by','details':'described_by'}
    result = {node:[] for node in nodes}
    for source,kind,target in relations:
        if kind not in inverse or source not in result or target not in result or source == target: continue
        forward = [kind,target]
        backward = [inverse[kind],source]
        if forward not in result[source]: result[source].append(forward)
        if backward not in result[target]: result[target].append(backward)
    return [[node,result[node]] for node in nodes]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('contract fixture 1', solve([['a','b',str(N),'alone'],[['a','label_for','b'],['a','description_for','b'],['b','controls',str(N)],['a','details',str(N)]]],), [['a',[['label_for','b'],['description_for','b'],['details',str(N)]]],['b',[['labelled_by','a'],['described_by','a'],['controls',str(N)]]],[str(N),[['controlled_by','b'],['details_for','a']]],['alone',[]]])
check('contract fixture 2', solve([['a','b'],[['a','controls','b'],['b','controls','a']]],), [['a',[['controls','b'],['controlled_by','b']]],['b',[['controlled_by','a'],['controls','a']]]])
check('contract fixture 3', solve([['a','b'],[['a','controls','b'],['a','controls','b']]],), [['a',[['controls','b']]],['b',[['controlled_by','a']]]])
check('contract fixture 4', solve([['a'],[['a','controls','a'],['a','unknown','a'],['a','controls','missing'],['missing','details','a']]],), [['a',[]]])
check('contract fixture 5', solve([['z','a'],[]],), [['z',[]],['a',[]]])
check('contract fixture 6', solve([[],[]],), [])
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
contract fixture 1[['a', [['label_for', 'b'], ['description_for', 'b'], ['details', '1']]], ['b', [['labelled_by', 'a'], ['described_by', 'a'], ['controls', '1']]], ['1', [['controlled_by', 'b'], ['described_by', 'a']]], ['alone', []]][['a', [['label_for', 'b'], ['description_for', 'b'], ['details', '1']]], ['b', [['labelled_by', 'a'], ['described_by', 'a'], ['controls', '1']]], ['1', [['controlled_by', 'b'], ['details_for', 'a']]], ['alone', []]]Failed
contract fixture 2[['a', [['controls', 'b'], ['controlled_by', 'b']]], ['b', [['controlled_by', 'a'], ['controls', 'a']]]][['a', [['controls', 'b'], ['controlled_by', 'b']]], ['b', [['controlled_by', 'a'], ['controls', 'a']]]]Passed
contract fixture 3[['a', [['controls', 'b']]], ['b', [['controlled_by', 'a']]]][['a', [['controls', 'b']]], ['b', [['controlled_by', 'a']]]]Passed
contract fixture 4[['a', []]][['a', []]]Passed
contract fixture 5[['z', []], ['a', []]][['z', []], ['a', []]]Passed
contract fixture 6[][]Passed

SHA-256 / 1c77ff8ef93084a56a590fac6112bf748ae5a1431bfb5248a6c0362a3ef9aa96

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 6 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

Stipulated finite adapter contract, not a claim of platform accessibility or ARIA conformance. 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 2026-09-29T14:45:47.060213+00:00.

Case digest / d3e3e2b4ac7df4376a6111a87ce0954035ca9ee666937248535e35251f38fba2