{"abstract":"Intersection chooses the least restrictive upper bound.","category":"Version constraints","checks":9,"contract":"Intersect all inclusive lower and exclusive upper bounds. None means unbounded. Return empty if lower >= upper, otherwise a bound pair.","contract_signature":"ranges","evaluation_group":"xt-constraint-intersection","failed_approach":"The attempted repair substitutes highs[0]. Fixture 3 still yields (3, 8) instead of (3, 6).","family":"xt-constraint-intersection-upper-reduction","id":"FA-9371","implementations":{"attempt":{"sha256":"50f57dca084b46679e1b5221d96e342a3a68452292ec95e64dc1d845af52e9dd","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ranges):\n    lows = [lo for lo, hi in ranges if lo is not None]\n    highs = [hi for lo, hi in ranges if hi is not None]\n    lo = max(lows) if lows else None\n    hi = highs[0] if highs else None\n    if lo is not None and hi is not None and lo >= hi: return 'empty'\n    return (lo, hi)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([]), (None, None))\ncheck('fixture 2', solve([(None, None)]), (None, None))\ncheck('fixture 3', solve([(1, 8), (3, 6)]), (3, 6))\ncheck('fixture 4', solve([(2, 2)]), 'empty')\ncheck('fixture 5', solve([(4, 2)]), 'empty')\ncheck('fixture 6', solve([(None, 3), (0, None)]), (0, 3))\ncheck('fixture 7', solve([(0, 3)]), (0, 3))\ncheck('fixture 8', solve([(0, None)]), (0, None))\ncheck('fixture 9', solve([(None, 0)]), (None, 0))\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":"006255e4ef58b630a9aae65640077b48e4294df6e413f8ef9386b0237126563e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ranges):\n    lows = [lo for lo, hi in ranges if lo is not None]\n    highs = [hi for lo, hi in ranges if hi is not None]\n    lo = max(lows) if lows else None\n    hi = max(highs) if highs else None\n    if lo is not None and hi is not None and lo >= hi: return 'empty'\n    return (lo, hi)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1', solve([]), (None, None))\ncheck('fixture 2', solve([(None, None)]), (None, None))\ncheck('fixture 3', solve([(1, 8), (3, 6)]), (3, 6))\ncheck('fixture 4', solve([(2, 2)]), 'empty')\ncheck('fixture 5', solve([(4, 2)]), 'empty')\ncheck('fixture 6', solve([(None, 3), (0, None)]), (0, 3))\ncheck('fixture 7', solve([(0, 3)]), (0, 3))\ncheck('fixture 8', solve([(0, None)]), (0, None))\ncheck('fixture 9', solve([(None, 0)]), (None, 0))\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":" 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":"xt-constraint-intersection-upper-reduction","generated_at":"2026-09-29T14:38:29.449267+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"An offline model of closed-open version range intersection, suitable for testing build and release tooling without external services.","root_cause":"The implementation substitutes max(highs) for min(highs), so intersection chooses the least restrictive upper bound.","sha256":"dd61b2f64a50747fe08e3b650ad943a99e5769b1fcb92083e1ac89374682458e","title":"Closed-open version range intersection: Intersection chooses the least restrictive upper bound · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.534,"exit_code":1,"observations":[{"actual":[null,null],"check":"fixture 1","expected":[null,null],"passed":true},{"actual":[null,null],"check":"fixture 2","expected":[null,null],"passed":true},{"actual":[3,8],"check":"fixture 3","expected":[3,6],"passed":false},{"actual":"empty","check":"fixture 4","expected":"empty","passed":true},{"actual":"empty","check":"fixture 5","expected":"empty","passed":true},{"actual":[0,3],"check":"fixture 6","expected":[0,3],"passed":true},{"actual":[0,3],"check":"fixture 7","expected":[0,3],"passed":true},{"actual":[0,null],"check":"fixture 8","expected":[0,null],"passed":true},{"actual":[null,0],"check":"fixture 9","expected":[null,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [3, 8], \"expected\": [3, 6], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": \"empty\", \"expected\": \"empty\", \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": \"empty\", \"expected\": \"empty\", \"passed\": true}, {\"check\": \"fixture 6\", \"actual\": [0, 3], \"expected\": [0, 3], \"passed\": true}, {\"check\": \"fixture 7\", \"actual\": [0, 3], \"expected\": [0, 3], \"passed\": true}, {\"check\": \"fixture 8\", \"actual\": [0, null], \"expected\": [0, null], \"passed\": true}, {\"check\": \"fixture 9\", \"actual\": [null, 0], \"expected\": [null, 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.365,"exit_code":1,"observations":[{"actual":[null,null],"check":"fixture 1","expected":[null,null],"passed":true},{"actual":[null,null],"check":"fixture 2","expected":[null,null],"passed":true},{"actual":[3,8],"check":"fixture 3","expected":[3,6],"passed":false},{"actual":"empty","check":"fixture 4","expected":"empty","passed":true},{"actual":"empty","check":"fixture 5","expected":"empty","passed":true},{"actual":[0,3],"check":"fixture 6","expected":[0,3],"passed":true},{"actual":[0,3],"check":"fixture 7","expected":[0,3],"passed":true},{"actual":[0,null],"check":"fixture 8","expected":[0,null],"passed":true},{"actual":[null,0],"check":"fixture 9","expected":[null,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [3, 8], \"expected\": [3, 6], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": \"empty\", \"expected\": \"empty\", \"passed\": true}, {\"check\": \"fixture 5\", \"actual\": \"empty\", \"expected\": \"empty\", \"passed\": true}, {\"check\": \"fixture 6\", \"actual\": [0, 3], \"expected\": [0, 3], \"passed\": true}, {\"check\": \"fixture 7\", \"actual\": [0, 3], \"expected\": [0, 3], \"passed\": true}, {\"check\": \"fixture 8\", \"actual\": [0, null], \"expected\": [0, null], \"passed\": true}, {\"check\": \"fixture 9\", \"actual\": [null, 0], \"expected\": [null, 0], \"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."}}