{"abstract":"Two omitted candidates acquire a fictitious pairwise preference.","category":"Voting rule computation","checks":6,"contract":"Return number of partial unique rankings preferring a over b; both omitted are tied, one ranked beats one omitted.","evaluation_group":"model-9ccbbca3c08d3bc3","failed_approach":"Counting a tie as a preference awards both-omitted ballots to the first candidate.","family":"z-voting_rules-pairwise-omission","id":"FA-12746","implementations":{"attempt":{"sha256":"d4c99e15ffc133b82e2033c7243977efd9c83b6a760083dc74eecacb375ff6ae","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ballots, a, b):\n    return sum((r.index(a) if a in r else len(r)) <= (r.index(b) if b in r else len(r)) for r in ballots)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ranked beats missing', solve([[0]]*N,0,1), N)\ncheck('both missing tie', solve([[]]*N,0,1), 0)\ncheck('missing loses', solve([[1]]*N,0,1), 0)\ncheck('rank order', solve([[1,0],[0,1]],0,1), 1)\ncheck('unrelated rank', solve([[2],[2,0]],0,1), 1)\ncheck('no ballots', solve([],0,1), 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":"9364b025e32e149a33fe7ee9c647f55188ab115087402595e14c7406284b02ea","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ballots, a, b):\n    return sum((r.index(a) if a in r else -1) < (r.index(b) if b in r else -1) for r in ballots)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ranked beats missing', solve([[0]]*N,0,1), N)\ncheck('both missing tie', solve([[]]*N,0,1), 0)\ncheck('missing loses', solve([[1]]*N,0,1), 0)\ncheck('rank order', solve([[1,0],[0,1]],0,1), 1)\ncheck('unrelated rank', solve([[2],[2,0]],0,1), 1)\ncheck('no ballots', solve([],0,1), 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"},"fixed":{"sha256":"90935265adedb4cd7045739e95fcc75d4f59d70e44ab8d15c4b3691f23217097","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(ballots, a, b):\n    return sum((r.index(a) if a in r else len(r)) < (r.index(b) if b in r else len(r)) for r in ballots)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('ranked beats missing', solve([[0]]*N,0,1), N)\ncheck('both missing tie', solve([[]]*N,0,1), 0)\ncheck('missing loses', solve([[1]]*N,0,1), 0)\ncheck('rank order', solve([[1,0],[0,1]],0,1), 1)\ncheck('unrelated rank', solve([[2],[2,0]],0,1), 1)\ncheck('no ballots', solve([],0,1), 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":"Abstract counting rules only; excludes jurisdictional law, ballot authentication and election operations. 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":"z-voting_rules-pairwise-omission","generated_at":"2026-09-29T14:38:59.790775+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic toy ballot model makes the stated counting convention executable.","repair":"Treat omitted candidates as tied below every ranked candidate.","root_cause":"A missing candidate receives an ordinary rank index.","sha256":"47da9eaa14ac80be453393847de0c76279a0a0422fcd3d31789e1a957def06a8","title":"Two omitted candidates acquire a fictitious pairwise preference · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":45.662,"exit_code":1,"observations":[{"actual":1,"check":"ranked beats missing","expected":1,"passed":true},{"actual":1,"check":"both missing tie","expected":0,"passed":false},{"actual":0,"check":"missing loses","expected":0,"passed":true},{"actual":1,"check":"rank order","expected":1,"passed":true},{"actual":2,"check":"unrelated rank","expected":1,"passed":false},{"actual":0,"check":"no ballots","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ranked beats missing\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"both missing tie\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"missing loses\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"rank order\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"unrelated rank\", \"actual\": 2, \"expected\": 1, \"passed\": false}, {\"check\": \"no ballots\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.565,"exit_code":1,"observations":[{"actual":0,"check":"ranked beats missing","expected":1,"passed":false},{"actual":0,"check":"both missing tie","expected":0,"passed":true},{"actual":1,"check":"missing loses","expected":0,"passed":false},{"actual":1,"check":"rank order","expected":1,"passed":true},{"actual":0,"check":"unrelated rank","expected":1,"passed":false},{"actual":0,"check":"no ballots","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ranked beats missing\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"both missing tie\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"missing loses\", \"actual\": 1, \"expected\": 0, \"passed\": false}, {\"check\": \"rank order\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"unrelated rank\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"no ballots\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":44.238,"exit_code":0,"observations":[{"actual":1,"check":"ranked beats missing","expected":1,"passed":true},{"actual":0,"check":"both missing tie","expected":0,"passed":true},{"actual":0,"check":"missing loses","expected":0,"passed":true},{"actual":1,"check":"rank order","expected":1,"passed":true},{"actual":1,"check":"unrelated rank","expected":1,"passed":true},{"actual":0,"check":"no ballots","expected":0,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"ranked beats missing\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"both missing tie\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"missing loses\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"rank order\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"unrelated rank\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"no ballots\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}