{"abstract":"Global keys remain hidden from earlier queries.","category":"Attention mask construction","checks":6,"contract":"Causal visibility plus globally visible key indices; special query positions still obey causality.","contract_signature":"length, global_keys","evaluation_group":"causal_special_global_key_v1","failed_approach":"Applying global status to query positions lets those rows see future keys.","family":"w3-attention-mask-construction-special-token-key","id":"FA-98226","implementations":{"attempt":{"sha256":"1a98423392fd29d4f700786e2e92b8fce89902bf7a299c26548d7522add6bba4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(length, global_keys):\n    return [[j<=i or i in global_keys or j in global_keys for j in range(length)] for i in range(length)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ng=[0]\ncheck('global keys only',solve(N+2,g),[[j<=i or j in g for j in range(N+2)] for i in range(N+2)])\ncheck('global-key exception applies to a query row',solve(3,[1])[0],[True,True,False])\ncheck('no globals',solve(3,[]),[[j<=i for j in range(3)] for i in range(3)])\ncheck('empty',solve(0,[]),[])\ncheck('singleton global key',solve(1,[0]),[[True]])\ncheck('later global key visible early',solve(3,[2])[1],[True,True,True])\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":"4e07470bc0cb5583dc88fd493f018e03c344500fec1fed1c4af66082f6e25dcf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(length, global_keys):\n    return [[j<=i for j in range(length)] for i in range(length)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ng=[0]\ncheck('global keys only',solve(N+2,g),[[j<=i or j in g for j in range(N+2)] for i in range(N+2)])\ncheck('global-key exception applies to a query row',solve(3,[1])[0],[True,True,False])\ncheck('no globals',solve(3,[]),[[j<=i for j in range(3)] for i in range(3)])\ncheck('empty',solve(0,[]),[])\ncheck('singleton global key',solve(1,[0]),[[True]])\ncheck('later global key visible early',solve(3,[2])[1],[True,True,True])\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":"These are toy Boolean matrix contracts; they do not define a production model architecture or tensor library behavior. 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":"w3-attention-mask-construction-special-token-key","generated_at":"2026-09-30T16:48:10.630274+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small explicit visibility matrix makes sequence-attention boundary behavior reviewable.","root_cause":"The mask applies causal order but never adds the global-key exception.","sha256":"3554407f74413cac96fe0d3c95364a9aee59e803f445372d2b2304e952726127","title":"Global keys remain hidden from earlier queries · case 01","variant":1,"variant_policy":"The fixture code references N, supplied as 1 through 5. Fixed boundary checks may repeat. These records share one mechanism and must remain together in evaluation splits.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":28.667,"exit_code":1,"observations":[{"actual":[[true,true,true],[true,true,false],[true,true,true]],"check":"global keys only","expected":[[true,false,false],[true,true,false],[true,true,true]],"passed":false},{"actual":[true,true,false],"check":"global-key exception applies to a query row","expected":[true,true,false],"passed":true},{"actual":[[true,false,false],[true,true,false],[true,true,true]],"check":"no globals","expected":[[true,false,false],[true,true,false],[true,true,true]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[true]],"check":"singleton global key","expected":[[true]],"passed":true},{"actual":[true,true,true],"check":"later global key visible early","expected":[true,true,true],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"global keys only\", \"actual\": [[true, true, true], [true, true, false], [true, true, true]], \"expected\": [[true, false, false], [true, true, false], [true, true, true]], \"passed\": false}, {\"check\": \"global-key exception applies to a query row\", \"actual\": [true, true, false], \"expected\": [true, true, false], \"passed\": true}, {\"check\": \"no globals\", \"actual\": [[true, false, false], [true, true, false], [true, true, true]], \"expected\": [[true, false, false], [true, true, false], [true, true, true]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"singleton global key\", \"actual\": [[true]], \"expected\": [[true]], \"passed\": true}, {\"check\": \"later global key visible early\", \"actual\": [true, true, true], \"expected\": [true, true, true], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":28.279,"exit_code":1,"observations":[{"actual":[[true,false,false],[true,true,false],[true,true,true]],"check":"global keys only","expected":[[true,false,false],[true,true,false],[true,true,true]],"passed":true},{"actual":[true,false,false],"check":"global-key exception applies to a query row","expected":[true,true,false],"passed":false},{"actual":[[true,false,false],[true,true,false],[true,true,true]],"check":"no globals","expected":[[true,false,false],[true,true,false],[true,true,true]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[true]],"check":"singleton global key","expected":[[true]],"passed":true},{"actual":[true,true,false],"check":"later global key visible early","expected":[true,true,true],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"global keys only\", \"actual\": [[true, false, false], [true, true, false], [true, true, true]], \"expected\": [[true, false, false], [true, true, false], [true, true, true]], \"passed\": true}, {\"check\": \"global-key exception applies to a query row\", \"actual\": [true, false, false], \"expected\": [true, true, false], \"passed\": false}, {\"check\": \"no globals\", \"actual\": [[true, false, false], [true, true, false], [true, true, true]], \"expected\": [[true, false, false], [true, true, false], [true, true, true]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"singleton global key\", \"actual\": [[true]], \"expected\": [[true]], \"passed\": true}, {\"check\": \"later global key visible early\", \"actual\": [true, true, false], \"expected\": [true, true, true], \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}