{"abstract":"Live-region mutation filtering emits irrelevant event kinds or loses text edits under the default policy.","category":"Accessibility interaction semantics","checks":6,"contract":"Events are [kind,text], where kind is additions, removals or text. Policy is None for default additions+text, or a list of relevant tokens; all admits all three kinds. An explicit empty list admits nothing. Return admitted texts in event order without deduplication. This model stops before priority, busy or speech queue scheduling.","evaluation_group":"model-b8420e0018f8d3c5","failed_approach":"Filtering explicit tokens works but interpreting an absent policy as additions-only drops text changes.","family":"z-accessibility-live-mutation-kind","id":"FA-11426","implementations":{"attempt":{"sha256":"26893a3dbbc1f256f853e98a88f18892ee99d71f2918083ae1dee946c67a9425","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, policy):\n    allowed = {'additions'} if policy is None else set(policy)\n    if 'all' in allowed: allowed = {'additions','removals','text'}\n    return [text for kind,text in events if kind in allowed]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('default includes edits', solve([('text',str(N)),('removals','gone')], None), [str(N)])\ncheck('addition policy excludes removal', solve([('removals','gone'),('additions',str(N))], ['additions']), [str(N)])\ncheck('all token expands', solve([('removals',str(N)),('text','new')], ['all']), [str(N),'new'])\ncheck('explicit empty', solve([('additions',str(N))], []), [])\ncheck('repeated distinct events retained', solve([('text',str(N)),('text',str(N))], ['text']), [str(N),str(N)])\ncheck('no mutations', solve([], None), [])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"e6d58d3b1d20818500f199644ca5d8f6433e46737dcdcfd6b521a3db042813d8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, policy):\n    return [text for kind,text in events]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('default includes edits', solve([('text',str(N)),('removals','gone')], None), [str(N)])\ncheck('addition policy excludes removal', solve([('removals','gone'),('additions',str(N))], ['additions']), [str(N)])\ncheck('all token expands', solve([('removals',str(N)),('text','new')], ['all']), [str(N),'new'])\ncheck('explicit empty', solve([('additions',str(N))], []), [])\ncheck('repeated distinct events retained', solve([('text',str(N)),('text',str(N))], ['text']), [str(N),str(N)])\ncheck('no mutations', solve([], None), [])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"4667f6b4cdb0591fcc506a91c750b5e4deed08b1ccdfc48d01b9848bff2d2730","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, policy):\n    allowed = {'additions','text'} if policy is None else set(policy)\n    if 'all' in allowed: allowed = {'additions','removals','text'}\n    return [text for kind,text in events if kind in allowed]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('default includes edits', solve([('text',str(N)),('removals','gone')], None), [str(N)])\ncheck('addition policy excludes removal', solve([('removals','gone'),('additions',str(N))], ['additions']), [str(N)])\ncheck('all token expands', solve([('removals',str(N)),('text','new')], ['all']), [str(N),'new'])\ncheck('explicit empty', solve([('additions',str(N))], []), [])\ncheck('repeated distinct events retained', solve([('text',str(N)),('text',str(N))], ['text']), [str(N),str(N)])\ncheck('no mutations', solve([], None), [])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":" 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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"z-accessibility-live-mutation-kind","generated_at":"2026-09-29T14:38:47.864642+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A controlled offline accessibility-data model. It isolates the stated contract; it does not simulate browser accessibility APIs or claim full ARIA conformance.","repair":"Expand the default and all policies, then preserve the order of events whose kind is admitted.","root_cause":"Every mutation is treated as a changed string without respecting the relevant event set.","sha256":"fa75b9540b2c237f6013cf29a1bd95a32bd6d4482e9579e979b3b130393001a5","title":"A removal is announced under an additions-only live policy · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.116,"exit_code":1,"observations":[{"actual":[],"check":"default includes edits","expected":["1"],"passed":false},{"actual":["1"],"check":"addition policy excludes removal","expected":["1"],"passed":true},{"actual":["1","new"],"check":"all token expands","expected":["1","new"],"passed":true},{"actual":[],"check":"explicit empty","expected":[],"passed":true},{"actual":["1","1"],"check":"repeated distinct events retained","expected":["1","1"],"passed":true},{"actual":[],"check":"no mutations","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"default includes edits\", \"actual\": [], \"expected\": [\"1\"], \"passed\": false}, {\"check\": \"addition policy excludes removal\", \"actual\": [\"1\"], \"expected\": [\"1\"], \"passed\": true}, {\"check\": \"all token expands\", \"actual\": [\"1\", \"new\"], \"expected\": [\"1\", \"new\"], \"passed\": true}, {\"check\": \"explicit empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"repeated distinct events retained\", \"actual\": [\"1\", \"1\"], \"expected\": [\"1\", \"1\"], \"passed\": true}, {\"check\": \"no mutations\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.287,"exit_code":1,"observations":[{"actual":["1","gone"],"check":"default includes edits","expected":["1"],"passed":false},{"actual":["gone","1"],"check":"addition policy excludes removal","expected":["1"],"passed":false},{"actual":["1","new"],"check":"all token expands","expected":["1","new"],"passed":true},{"actual":["1"],"check":"explicit empty","expected":[],"passed":false},{"actual":["1","1"],"check":"repeated distinct events retained","expected":["1","1"],"passed":true},{"actual":[],"check":"no mutations","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"default includes edits\", \"actual\": [\"1\", \"gone\"], \"expected\": [\"1\"], \"passed\": false}, {\"check\": \"addition policy excludes removal\", \"actual\": [\"gone\", \"1\"], \"expected\": [\"1\"], \"passed\": false}, {\"check\": \"all token expands\", \"actual\": [\"1\", \"new\"], \"expected\": [\"1\", \"new\"], \"passed\": true}, {\"check\": \"explicit empty\", \"actual\": [\"1\"], \"expected\": [], \"passed\": false}, {\"check\": \"repeated distinct events retained\", \"actual\": [\"1\", \"1\"], \"expected\": [\"1\", \"1\"], \"passed\": true}, {\"check\": \"no mutations\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.279,"exit_code":0,"observations":[{"actual":["1"],"check":"default includes edits","expected":["1"],"passed":true},{"actual":["1"],"check":"addition policy excludes removal","expected":["1"],"passed":true},{"actual":["1","new"],"check":"all token expands","expected":["1","new"],"passed":true},{"actual":[],"check":"explicit empty","expected":[],"passed":true},{"actual":["1","1"],"check":"repeated distinct events retained","expected":["1","1"],"passed":true},{"actual":[],"check":"no mutations","expected":[],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"default includes edits\", \"actual\": [\"1\"], \"expected\": [\"1\"], \"passed\": true}, {\"check\": \"addition policy excludes removal\", \"actual\": [\"1\"], \"expected\": [\"1\"], \"passed\": true}, {\"check\": \"all token expands\", \"actual\": [\"1\", \"new\"], \"expected\": [\"1\", \"new\"], \"passed\": true}, {\"check\": \"explicit empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"repeated distinct events retained\", \"actual\": [\"1\", \"1\"], \"expected\": [\"1\", \"1\"], \"passed\": true}, {\"check\": \"no mutations\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}