{"abstract":"overlapping windows are retained as training examples.","category":"Dataset split isolation","checks":6,"contract":"Intervals [id,start,end] use half-open ranges; keep training intervals with end<=lo or start>=hi.","contract_signature":"intervals, lo, hi","evaluation_group":"ds-purge-intervals","failed_approach":"Removing intervals whose start lies inside validation leaves intervals that began earlier but overlap.","family":"w3-dataset-split-isolation-purge-overlapping-intervals","id":"FA-97866","implementations":{"attempt":{"sha256":"f5b9b374c8929a125b24d394930d8bd9fe1844809103287b697872399b7b6db1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(intervals, lo, hi):\n    return sorted(i for i,s,e in intervals if not (lo<=s<hi))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('left adjacent',solve([['a',0,N]],N,N+2),['a'])\ncheck('overlap from left',solve([['a',N-2,N+1]],N,N+2),[])\ncheck('inside',solve([['a',N,N+1]],N,N+2),[])\ncheck('right adjacent',solve([['a',N+2,N+4]],N,N+2),['a'])\ncheck('empty',solve([],N,N+2),[])\ncheck('zero length',solve([['a',N,N]],N,N+2),['a'])\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":"14a46e1ec1abeab40d51ac64e4f56af6beb8bbf5fd79d7df26e99dc1c1fa4f71","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(intervals, lo, hi):\n    return sorted(i for i,s,e in intervals if s<hi and e>lo)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('left adjacent',solve([['a',0,N]],N,N+2),['a'])\ncheck('overlap from left',solve([['a',N-2,N+1]],N,N+2),[])\ncheck('inside',solve([['a',N,N+1]],N,N+2),[])\ncheck('right adjacent',solve([['a',N+2,N+4]],N,N+2),['a'])\ncheck('empty',solve([],N,N+2),[])\ncheck('zero length',solve([['a',N,N]],N,N+2),['a'])\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 small in-memory records with self-contained contracts; no claim is made about production sampling quality. 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-dataset-split-isolation-purge-overlapping-intervals","generated_at":"2026-09-30T16:48:06.687641+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This toy split allocator makes membership rules explicit for reproducible evaluation fixtures.","root_cause":"The overlap predicate identifies intervals that intersect validation and mistakenly returns those conflicts as training data.","sha256":"3b706de869a6a2f8b99b391dfc9c4f6efdc37a69ccbe5ffeab70b379eeff84f4","title":"Dataset split: overlapping windows are retained as training examples · 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":25.945,"exit_code":1,"observations":[{"actual":["a"],"check":"left adjacent","expected":["a"],"passed":true},{"actual":["a"],"check":"overlap from left","expected":[],"passed":false},{"actual":[],"check":"inside","expected":[],"passed":true},{"actual":["a"],"check":"right adjacent","expected":["a"],"passed":true},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[],"check":"zero length","expected":["a"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"left adjacent\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"overlap from left\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"inside\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"right adjacent\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"zero length\", \"actual\": [], \"expected\": [\"a\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":30.753,"exit_code":1,"observations":[{"actual":[],"check":"left adjacent","expected":["a"],"passed":false},{"actual":["a"],"check":"overlap from left","expected":[],"passed":false},{"actual":["a"],"check":"inside","expected":[],"passed":false},{"actual":[],"check":"right adjacent","expected":["a"],"passed":false},{"actual":[],"check":"empty","expected":[],"passed":true},{"actual":[],"check":"zero length","expected":["a"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"left adjacent\", \"actual\": [], \"expected\": [\"a\"], \"passed\": false}, {\"check\": \"overlap from left\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"inside\", \"actual\": [\"a\"], \"expected\": [], \"passed\": false}, {\"check\": \"right adjacent\", \"actual\": [], \"expected\": [\"a\"], \"passed\": false}, {\"check\": \"empty\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"zero length\", \"actual\": [], \"expected\": [\"a\"], \"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."}}