{"abstract":"Shifted pairs carry an off-by-one context position.","category":"Autoregressive target shifting","checks":6,"contract":"Given equally aligned input and next-target lists plus an origin, return [context_position,input,target] rows; ignore unmatched suffixes.","contract_signature":"inputs, targets, origin","evaluation_group":"w3-ars-position_supervision","failed_approach":"Resetting the position counter to zero repairs only streams whose origin is zero.","family":"w3-autoregressive-target-shifting-position-index-start","id":"FA-98301","implementations":{"attempt":{"sha256":"a2696e2fc3d79191124e9a2e1ee730e1c155834a81932f2ff404a74ed9d287c9","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(inputs, targets, origin):\n    return [[i,inputs[i],targets[i]] for i in range(min(len(inputs),len(targets)))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('nonzero origin',solve([5,6],[8,9],N),[[N,5,8],[N+1,6,9]])\ncheck('zero origin',solve([8],[3],0),[[0,8,3]])\ncheck('negative origin',solve([1,2],[7,8],-2),[[-2,1,7],[-1,2,8]])\ncheck('empty',solve([],[],N),[])\ncheck('unmatched target',solve([4],[9,10],7),[[7,4,9]])\ncheck('unmatched input',solve([4,5],[9],20),[[20,4,9]])\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":"2aef22566ff4529eb9813c763c01182835784670ce08f6ce6d69a86415d1b471","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(inputs, targets, origin):\n    return [[origin+i+1,inputs[i],targets[i]] for i in range(min(len(inputs),len(targets)))]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('nonzero origin',solve([5,6],[8,9],N),[[N,5,8],[N+1,6,9]])\ncheck('zero origin',solve([8],[3],0),[[0,8,3]])\ncheck('negative origin',solve([1,2],[7,8],-2),[[-2,1,7],[-1,2,8]])\ncheck('empty',solve([],[],N),[])\ncheck('unmatched target',solve([4],[9,10],7),[[7,4,9]])\ncheck('unmatched input',solve([4,5],[9],20),[[20,4,9]])\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":"Inputs are toy integer token sequences; this contract says nothing about model quality, batching, sampling, or production training frameworks. 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-autoregressive-target-shifting-position-index-start","generated_at":"2026-09-30T16:48:11.500551+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A small deterministic token-stream contract makes next-token alignment errors inspectable.","root_cause":"The pair emitter labels the first input with origin plus one instead of the declared origin.","sha256":"41755f6b0021349085b1d522f28d7b7748c85d8430c51d7e625c965e04568aba","title":"Shifted pairs carry an off-by-one context position · 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":29.2,"exit_code":1,"observations":[{"actual":[[0,5,8],[1,6,9]],"check":"nonzero origin","expected":[[1,5,8],[2,6,9]],"passed":false},{"actual":[[0,8,3]],"check":"zero origin","expected":[[0,8,3]],"passed":true},{"actual":[[0,1,7],[1,2,8]],"check":"negative origin","expected":[[-2,1,7],[-1,2,8]],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[0,4,9]],"check":"unmatched target","expected":[[7,4,9]],"passed":false},{"actual":[[0,4,9]],"check":"unmatched input","expected":[[20,4,9]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"nonzero origin\", \"actual\": [[0, 5, 8], [1, 6, 9]], \"expected\": [[1, 5, 8], [2, 6, 9]], \"passed\": false}, {\"check\": \"zero origin\", \"actual\": [[0, 8, 3]], \"expected\": [[0, 8, 3]], \"passed\": true}, {\"check\": \"negative origin\", \"actual\": [[0, 1, 7], [1, 2, 8]], \"expected\": [[-2, 1, 7], [-1, 2, 8]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"unmatched target\", \"actual\": [[0, 4, 9]], \"expected\": [[7, 4, 9]], \"passed\": false}, {\"check\": \"unmatched input\", \"actual\": [[0, 4, 9]], \"expected\": [[20, 4, 9]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":27.915,"exit_code":1,"observations":[{"actual":[[2,5,8],[3,6,9]],"check":"nonzero origin","expected":[[1,5,8],[2,6,9]],"passed":false},{"actual":[[1,8,3]],"check":"zero origin","expected":[[0,8,3]],"passed":false},{"actual":[[-1,1,7],[0,2,8]],"check":"negative origin","expected":[[-2,1,7],[-1,2,8]],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[8,4,9]],"check":"unmatched target","expected":[[7,4,9]],"passed":false},{"actual":[[21,4,9]],"check":"unmatched input","expected":[[20,4,9]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"nonzero origin\", \"actual\": [[2, 5, 8], [3, 6, 9]], \"expected\": [[1, 5, 8], [2, 6, 9]], \"passed\": false}, {\"check\": \"zero origin\", \"actual\": [[1, 8, 3]], \"expected\": [[0, 8, 3]], \"passed\": false}, {\"check\": \"negative origin\", \"actual\": [[-1, 1, 7], [0, 2, 8]], \"expected\": [[-2, 1, 7], [-1, 2, 8]], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"unmatched target\", \"actual\": [[8, 4, 9]], \"expected\": [[7, 4, 9]], \"passed\": false}, {\"check\": \"unmatched input\", \"actual\": [[21, 4, 9]], \"expected\": [[20, 4, 9]], \"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."}}