{"abstract":"Congestion loss threshold has two segment floor.","category":"Transport flow control","checks":4,"contract":"Bounded offline decision model: congestion loss threshold has two segment floor. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.","evaluation_group":"xh-congestion-loss-threshold-has-two-segment-floor","failed_approach":"The attempted repair uses `min(flight//2,2*segment)` and still violates a separate fixture.","family":"xh-congestion-loss-threshold-has-two-segment-floor","id":"FA-7271","implementations":{"attempt":{"sha256":"f5c5b064ef79b12f6bf1bd59b20c9ac583ca0f9ae185401addbe0d44898bb17d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(flight, segment):\n    return min(flight//2,2*segment)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(2, 2), 4)\", \"check('fixture 2', solve(20, 2), 10)\", \"check('fixture 3', solve(0, 1), 2)\", \"check('fixture 4', solve(8, 2), 4)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"85ba6efdcf33a09a6c018c32f79e0535c6ce350b8a1e7c77d8b4cd27915cc3e5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(flight, segment):\n    return flight//2\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(2, 2), 4)\", \"check('fixture 2', solve(20, 2), 10)\", \"check('fixture 3', solve(0, 1), 2)\", \"check('fixture 4', solve(8, 2), 4)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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"},"fixed":{"sha256":"6269aafaf1a641d382934da7bbd928785d10c50007cb9c3e4e31a43e46429755","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(flight, segment):\n    return max(flight//2,2*segment)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(2, 2), 4)\", \"check('fixture 2', solve(20, 2), 10)\", \"check('fixture 3', solve(0, 1), 2)\", \"check('fixture 4', solve(8, 2), 4)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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":"xh-congestion-loss-threshold-has-two-segment-floor","generated_at":"2026-09-29T14:38:09.970506+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic transport flow control model isolates the congestion-loss-threshold-has-two-segment-floor policy at a network component boundary.","repair":"Apply the explicit congestion-loss-threshold-has-two-segment-floor contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `flight//2` for the congestion-loss-threshold-has-two-segment-floor decision.","sha256":"eed864ba80904b561fecf9a0d5c7a0b717b9bf3c35cefcc6cdf8e29be2c0f3d1","title":"Congestion loss threshold has two segment floor · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":52.666,"exit_code":1,"observations":[{"actual":4,"check":"fixture 2","expected":10,"passed":false},{"actual":0,"check":"fixture 3","expected":2,"passed":false},{"actual":4,"check":"fixture 4","expected":4,"passed":true},{"actual":1,"check":"fixture 1","expected":4,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 4, \"expected\": 10, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 2, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 1, \"expected\": 4, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":50.13,"exit_code":1,"observations":[{"actual":10,"check":"fixture 2","expected":10,"passed":true},{"actual":0,"check":"fixture 3","expected":2,"passed":false},{"actual":4,"check":"fixture 4","expected":4,"passed":true},{"actual":1,"check":"fixture 1","expected":4,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 0, \"expected\": 2, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 1, \"expected\": 4, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":46.753,"exit_code":0,"observations":[{"actual":10,"check":"fixture 2","expected":10,"passed":true},{"actual":2,"check":"fixture 3","expected":2,"passed":true},{"actual":4,"check":"fixture 4","expected":4,"passed":true},{"actual":4,"check":"fixture 1","expected":4,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 4, \"expected\": 4, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}