FAILURE MAP
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FA-53401 / Accessibility interaction semantics / Open access

Unresolved source identifiers produce dangling relations · case 01

Unresolved source identifiers produce dangling relations.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The source presence decision in the relation scope adapter violates its declared contract.

THE FAILURE

The source presence decision in the relation scope adapter violates its declared contract.

Unsuccessful approach: The local repair substitutes if target is None: continue source = source or (si != '',False) but still mishandles the regression fixtures.

Case contract

Input [nodes,requests] with nodes [document,id,exposed,defunct] and requests [source_doc,source_id,target_doc,target_id,kind]. Allowed kinds details, controls, describedby. Resolve in document-scoped ID space, reject missing/hidden/defunct sources or targets, self edges, cross-document edges and unsupported kinds. Dedupe identical edges preserving request order. Return [source_id,kind,target_id]. IDs may repeat in different documents. Source and target visibility are direct snapshot flags, not ancestry.

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,requests = data
    index = {(doc,ident):(visible,dead) for doc,ident,visible,dead in nodes}
    result = []
    seen = set()
    for sd,si,td,ti,kind in requests:
        if kind not in {'details','controls','describedby'}: continue
        if sd != td: continue
        source = index.get((sd,si))
        target = index.get((td,ti))
        if target is None: continue
        source = source or (True,False)
        if not source[0] or source[1]: continue
        if not target[0] or target[1]: continue
        if si == ti: continue
        edge = (si,kind,ti)
        if edge in seen: continue
        seen.add(edge)
        result.append(list(edge))
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('valid ordered and repeated', solve([[['d','s',True,False],['d','t',True,False],['d',str(N),True,False]],[['d','s','d','t','details'],['d','s','d',str(N),'controls'],['d','s','d','t','details']]],), [['s','details','t'],['s','controls',str(N)]])
check('different kinds same endpoints', solve([[['d','s',True,False],['d','t',True,False]],[['d','s','d','t','details'],['d','s','d','t','controls']]],), [['s','details','t'],['s','controls','t']])
check('cross document collision', solve([[['d','s',True,False],['d','t',False,False],['e','t',True,False]],[['d','s','e','t','details'],['d','s','d','t','details']]],), [])
check('unsupported and self', solve([[['d','s',True,False],['d','t',True,False]],[['d','s','d','t','label'],['d','s','d','s','controls']]],), [])
check('missing endpoints', solve([[['d','s',True,False]],[['d','s','d','missing','details'],['d','gone','d','s','details']]],), [])
check('hidden source', solve([[['d','s',False,False],['d','t',True,False]],[['d','s','d','t','details']]],), [])
check('defunct source', solve([[['d','s',True,True],['d','t',True,False]],[['d','s','d','t','details']]],), [])
check('defunct target', solve([[['d','s',True,False],['d','t',True,True]],[['d','s','d','t','details']]],), [])
check('empty snapshot', 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
valid ordered and repeated[['s', 'details', 't'], ['s', 'controls', '1']][['s', 'details', 't'], ['s', 'controls', '1']]Passed
different kinds same endpoints[['s', 'details', 't'], ['s', 'controls', 't']][['s', 'details', 't'], ['s', 'controls', 't']]Passed
cross document collision[][]Passed
unsupported and self[][]Passed
missing endpoints[['gone', 'details', 's']][]Failed
hidden source[][]Passed
defunct source[][]Passed
defunct target[][]Passed
empty snapshot[][]Passed

SHA-256 / 761a16ee5c95d7a492e5213482b0b7444037de35730e008e3b1aa54d88f61e67

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(data):
    nodes,requests = data
    index = {(doc,ident):(visible,dead) for doc,ident,visible,dead in nodes}
    result = []
    seen = set()
    for sd,si,td,ti,kind in requests:
        if kind not in {'details','controls','describedby'}: continue
        if sd != td: continue
        source = index.get((sd,si))
        target = index.get((td,ti))
        if target is None: continue
        source = source or (si != '',False)
        if not source[0] or source[1]: continue
        if not target[0] or target[1]: continue
        if si == ti: continue
        edge = (si,kind,ti)
        if edge in seen: continue
        seen.add(edge)
        result.append(list(edge))
    return result
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('valid ordered and repeated', solve([[['d','s',True,False],['d','t',True,False],['d',str(N),True,False]],[['d','s','d','t','details'],['d','s','d',str(N),'controls'],['d','s','d','t','details']]],), [['s','details','t'],['s','controls',str(N)]])
check('different kinds same endpoints', solve([[['d','s',True,False],['d','t',True,False]],[['d','s','d','t','details'],['d','s','d','t','controls']]],), [['s','details','t'],['s','controls','t']])
check('cross document collision', solve([[['d','s',True,False],['d','t',False,False],['e','t',True,False]],[['d','s','e','t','details'],['d','s','d','t','details']]],), [])
check('unsupported and self', solve([[['d','s',True,False],['d','t',True,False]],[['d','s','d','t','label'],['d','s','d','s','controls']]],), [])
check('missing endpoints', solve([[['d','s',True,False]],[['d','s','d','missing','details'],['d','gone','d','s','details']]],), [])
check('hidden source', solve([[['d','s',False,False],['d','t',True,False]],[['d','s','d','t','details']]],), [])
check('defunct source', solve([[['d','s',True,True],['d','t',True,False]],[['d','s','d','t','details']]],), [])
check('defunct target', solve([[['d','s',True,False],['d','t',True,True]],[['d','s','d','t','details']]],), [])
check('empty snapshot', 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
valid ordered and repeated[['s', 'details', 't'], ['s', 'controls', '1']][['s', 'details', 't'], ['s', 'controls', '1']]Passed
different kinds same endpoints[['s', 'details', 't'], ['s', 'controls', 't']][['s', 'details', 't'], ['s', 'controls', 't']]Passed
cross document collision[][]Passed
unsupported and self[][]Passed
missing endpoints[['gone', 'details', 's']][]Failed
hidden source[][]Passed
defunct source[][]Passed
defunct target[][]Passed
empty snapshot[][]Passed

SHA-256 / 99b24a8f74181300c07960b8d34d67a4f2628e757312b266c9e6c4bd0a7419e5

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 9 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 2026-09-29T14:45:38.681583+00:00.

Case digest / 2455275e5c58739882755ac7749478991ee762723fc1d27a9f4700520d3f36f2