{"abstract":"Padded query rows can attend to real keys.","category":"Attention mask construction","checks":6,"contract":"Square matrix; pair visibility requires query valid, key valid and key<=query.","contract_signature":"valid","evaluation_group":"query_key_padding_v1","failed_approach":"Masking only query validity still exposes padded key positions from a valid query.","family":"w3-attention-mask-construction-query-padding-rows","id":"FA-98151","implementations":{"attempt":{"sha256":"fd34e97425eca81a1a0eebc6f8544ecaaf01c90dfc8d0f90fa3142b729ef0aeb","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(valid):\n    return [[bool(valid[i]) and j<=i for j in range(len(valid))] for i in range(len(valid))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nv=[True]*N+[False]\ncheck('padded query row',solve(v),[[bool(v[i]) and bool(v[j]) and j<=i for j in range(N+1)] for i in range(N+1)])\ncheck('active query',solve([True,True]),[[True,False],[True,True]])\ncheck('all invalid',solve([False,False]),[[False,False],[False,False]])\ncheck('empty',solve([]),[])\ncheck('singleton invalid',solve([False]),[[False]])\ncheck('interior pad',solve([True,False,True]),[[True,False,False],[False,False,False],[True,False,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":"29b4af6e1b85fdedf701c5e5b7988accdc80fe1bb039c79420c9c27607886fd7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(valid):\n    return [[bool(valid[j]) and j<=i for j in range(len(valid))] for i in range(len(valid))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nv=[True]*N+[False]\ncheck('padded query row',solve(v),[[bool(v[i]) and bool(v[j]) and j<=i for j in range(N+1)] for i in range(N+1)])\ncheck('active query',solve([True,True]),[[True,False],[True,True]])\ncheck('all invalid',solve([False,False]),[[False,False],[False,False]])\ncheck('empty',solve([]),[])\ncheck('singleton invalid',solve([False]),[[False]])\ncheck('interior pad',solve([True,False,True]),[[True,False,False],[False,False,False],[True,False,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-query-padding-rows","generated_at":"2026-09-30T16:48:09.757508+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":"Only key padding is considered, so invalid query rows are populated.","sha256":"19f6450e84f76799c707434ed2071f3c9fe55e78e622c012c018e2cc70ba69d1","title":"Padded query rows can attend to real keys · 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":28.274,"exit_code":1,"observations":[{"actual":[[true,false],[false,false]],"check":"padded query row","expected":[[true,false],[false,false]],"passed":true},{"actual":[[true,false],[true,true]],"check":"active query","expected":[[true,false],[true,true]],"passed":true},{"actual":[[false,false],[false,false]],"check":"all invalid","expected":[[false,false],[false,false]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[false]],"check":"singleton invalid","expected":[[false]],"passed":true},{"actual":[[true,false,false],[false,false,false],[true,true,true]],"check":"interior pad","expected":[[true,false,false],[false,false,false],[true,false,true]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"padded query row\", \"actual\": [[true, false], [false, false]], \"expected\": [[true, false], [false, false]], \"passed\": true}, {\"check\": \"active query\", \"actual\": [[true, false], [true, true]], \"expected\": [[true, false], [true, true]], \"passed\": true}, {\"check\": \"all invalid\", \"actual\": [[false, false], [false, false]], \"expected\": [[false, false], [false, false]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"singleton invalid\", \"actual\": [[false]], \"expected\": [[false]], \"passed\": true}, {\"check\": \"interior pad\", \"actual\": [[true, false, false], [false, false, false], [true, true, true]], \"expected\": [[true, false, false], [false, false, false], [true, false, true]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":25.512,"exit_code":1,"observations":[{"actual":[[true,false],[true,false]],"check":"padded query row","expected":[[true,false],[false,false]],"passed":false},{"actual":[[true,false],[true,true]],"check":"active query","expected":[[true,false],[true,true]],"passed":true},{"actual":[[false,false],[false,false]],"check":"all invalid","expected":[[false,false],[false,false]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[false]],"check":"singleton invalid","expected":[[false]],"passed":true},{"actual":[[true,false,false],[true,false,false],[true,false,true]],"check":"interior pad","expected":[[true,false,false],[false,false,false],[true,false,true]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"padded query row\", \"actual\": [[true, false], [true, false]], \"expected\": [[true, false], [false, false]], \"passed\": false}, {\"check\": \"active query\", \"actual\": [[true, false], [true, true]], \"expected\": [[true, false], [true, true]], \"passed\": true}, {\"check\": \"all invalid\", \"actual\": [[false, false], [false, false]], \"expected\": [[false, false], [false, false]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"singleton invalid\", \"actual\": [[false]], \"expected\": [[false]], \"passed\": true}, {\"check\": \"interior pad\", \"actual\": [[true, false, false], [true, false, false], [true, false, true]], \"expected\": [[true, false, false], [false, false, false], [true, false, 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."}}