{"abstract":"Separator tokens are omitted from the packing budget.","category":"Sequence batch packing","checks":6,"contract":"Pack in order, counting one separator token between adjacent sequences in each bin; output bins preserve original sequences.","contract_signature":"sequences, capacity, separator","evaluation_group":"w3-seqpack-separator-budget-v1","failed_approach":"Charging two separators splits a bin that fits with exactly one.","family":"w3-sequence-batch-packing-token-budget-separator","id":"FA-98066","implementations":{"attempt":{"sha256":"2922f332e536906b15a35b83330d6c4afc29739ad657937b3642c0bd74ccccdc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(sequences, capacity, separator):\n    bins=[]; cur=[]; used=0\n    for s in sequences:\n        cost=len(s)+(2 if cur else 0)\n        if cur and used+cost>capacity: bins.append(cur); cur=[]; used=0; cost=len(s)\n        cur.append(s); used+=cost\n    if cur: bins.append(cur)\n    return bins\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\na=[1]*N\ncheck('separator tips over', solve([a,[2]],N+1,99), [[a],[[2]]])\ncheck('separator exact', solve([a,[2]],N+2,99), [[a,[2]]])\ncheck('single no separator', solve([a],N,99), [[a]])\ncheck('empty', solve([],N,99), [])\ncheck('three sequences', solve([[1],[2],[3]],5,99), [[[1],[2],[3]]])\ncheck('independent bins', solve([[1]*N,[2]*N],N,99), [[[1]*N],[[2]*N]])\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":"074ce8b8964dc69642b4e10787628beaae8c242bcfbdd6da9ee73034fcdaa733","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(sequences, capacity, separator):\n    bins=[]; cur=[]; used=0\n    for s in sequences:\n        cost=len(s)\n        if cur and used+cost>capacity: bins.append(cur); cur=[]; used=0; cost=len(s)\n        cur.append(s); used+=cost\n    if cur: bins.append(cur)\n    return bins\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\na=[1]*N\ncheck('separator tips over', solve([a,[2]],N+1,99), [[a],[[2]]])\ncheck('separator exact', solve([a,[2]],N+2,99), [[a,[2]]])\ncheck('single no separator', solve([a],N,99), [[a]])\ncheck('empty', solve([],N,99), [])\ncheck('three sequences', solve([[1],[2],[3]],5,99), [[[1],[2],[3]]])\ncheck('independent bins', solve([[1]*N,[2]*N],N,99), [[[1]*N],[[2]*N]])\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 short integer-token lists under the stated toy contract; results do not claim compatibility with a specific training framework. 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-sequence-batch-packing-token-budget-separator","generated_at":"2026-09-30T16:48:08.896751+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic toy packing rule models a common boundary in preparing bounded training sequences.","root_cause":"The accounting omits the inter-sequence separator cost.","sha256":"96ef5f7268bdabfb2e4c58f209c2c415b432f63163bccc8c7451dd5159ab9f3e","title":"Separator tokens are omitted from the packing budget · 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":29.505,"exit_code":1,"observations":[{"actual":[[[1]],[[2]]],"check":"separator tips over","expected":[[[1]],[[2]]],"passed":true},{"actual":[[[1]],[[2]]],"check":"separator exact","expected":[[[1],[2]]],"passed":false},{"actual":[[[1]]],"check":"single no separator","expected":[[[1]]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[[1],[2]],[[3]]],"check":"three sequences","expected":[[[1],[2],[3]]],"passed":false},{"actual":[[[1]],[[2]]],"check":"independent bins","expected":[[[1]],[[2]]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"separator tips over\", \"actual\": [[[1]], [[2]]], \"expected\": [[[1]], [[2]]], \"passed\": true}, {\"check\": \"separator exact\", \"actual\": [[[1]], [[2]]], \"expected\": [[[1], [2]]], \"passed\": false}, {\"check\": \"single no separator\", \"actual\": [[[1]]], \"expected\": [[[1]]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"three sequences\", \"actual\": [[[1], [2]], [[3]]], \"expected\": [[[1], [2], [3]]], \"passed\": false}, {\"check\": \"independent bins\", \"actual\": [[[1]], [[2]]], \"expected\": [[[1]], [[2]]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":29.149,"exit_code":1,"observations":[{"actual":[[[1],[2]]],"check":"separator tips over","expected":[[[1]],[[2]]],"passed":false},{"actual":[[[1],[2]]],"check":"separator exact","expected":[[[1],[2]]],"passed":true},{"actual":[[[1]]],"check":"single no separator","expected":[[[1]]],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[[[1],[2],[3]]],"check":"three sequences","expected":[[[1],[2],[3]]],"passed":true},{"actual":[[[1]],[[2]]],"check":"independent bins","expected":[[[1]],[[2]]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"separator tips over\", \"actual\": [[[1], [2]]], \"expected\": [[[1]], [[2]]], \"passed\": false}, {\"check\": \"separator exact\", \"actual\": [[[1], [2]]], \"expected\": [[[1], [2]]], \"passed\": true}, {\"check\": \"single no separator\", \"actual\": [[[1]]], \"expected\": [[[1]]], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"three sequences\", \"actual\": [[[1], [2], [3]]], \"expected\": [[[1], [2], [3]]], \"passed\": true}, {\"check\": \"independent bins\", \"actual\": [[[1]], [[2]]], \"expected\": [[[1]], [[2]]], \"passed\": true}], \"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."}}