{"abstract":"A scalar or lexicographic comparison imposes an order on independent replica updates.","category":"Distributed coordination","checks":7,"contract":"Given two maps from replica ID to nonnegative counter, return equal, before, after, or concurrent. Before requires every component <= and at least one <; after is its inverse.","contract_signature":"left, right","evaluation_group":"model-b10ca64c5437ec91","failed_approach":"Lexicographic comparison is deterministic but incorrectly orders incomparable clocks.","family":"dist-vector-clock-order","id":"FA-061","implementations":{"attempt":{"sha256":"cca318cac9388bdb2fdd6934cabc63ff471e40998819b6af9df6964cb8211cc5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(left, right):\n    keys = sorted(set(left) | set(right))\n    a = tuple(left.get(k, 0) for k in keys)\n    b = tuple(right.get(k, 0) for k in keys)\n    return 'equal' if a == b else ('before' if a < b else 'after')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('same-sum independent writes', solve({'a': N+1}, {'a': N, 'b': 1}), 'concurrent')\ncheck('unequal-sum concurrent writes', solve({'a': N+2}, {'a': N, 'b': 1}), 'concurrent')\ncheck('strict causal extension', solve({'a': N}, {'a': N, 'b': N}), 'before')\ncheck('reverse causal extension', solve({'a': N+1, 'b': N}, {'a': N}), 'after')\ncheck('missing zero component', solve({'a': N}, {'a': N, 'b': 0}), 'equal')\ncheck('empty clocks', solve({}, {}), 'equal')\ncheck('one replica progresses', solve({'a': N}, {'a': N+1}), 'before')\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":"069bcfd225d3871975da9c0c471188d43cbce9adb319dfe958402228becf4c7a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(left, right):\n    a, b = sum(left.values()), sum(right.values())\n    return 'equal' if a == b else ('before' if a < b else 'after')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('same-sum independent writes', solve({'a': N+1}, {'a': N, 'b': 1}), 'concurrent')\ncheck('unequal-sum concurrent writes', solve({'a': N+2}, {'a': N, 'b': 1}), 'concurrent')\ncheck('strict causal extension', solve({'a': N}, {'a': N, 'b': N}), 'before')\ncheck('reverse causal extension', solve({'a': N+1, 'b': N}, {'a': N}), 'after')\ncheck('missing zero component', solve({'a': N}, {'a': N, 'b': 0}), 'equal')\ncheck('empty clocks', solve({}, {}), 'equal')\ncheck('one replica progresses', solve({'a': N}, {'a': N+1}), 'before')\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":"dist-vector-clock-order","generated_at":"2026-09-29T14:36:49.895809+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Models conflict detection for replicated revisions; a total order can silently hide conflicts that require application-specific reconciliation.","root_cause":"Vector clocks encode a partial order, not a ranking by total counter size or replica name.","sha256":"f53f8d900e37e4b8e35989d6c4204cc115d214d346d37cbd9a24c5ea3fcc1a7d","title":"Concurrent revisions are mistaken for causal successors · 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":32.342,"exit_code":1,"observations":[{"actual":"after","check":"same-sum independent writes","expected":"concurrent","passed":false},{"actual":"after","check":"unequal-sum concurrent writes","expected":"concurrent","passed":false},{"actual":"before","check":"strict causal extension","expected":"before","passed":true},{"actual":"after","check":"reverse causal extension","expected":"after","passed":true},{"actual":"equal","check":"missing zero component","expected":"equal","passed":true},{"actual":"equal","check":"empty clocks","expected":"equal","passed":true},{"actual":"before","check":"one replica progresses","expected":"before","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"same-sum independent writes\", \"actual\": \"after\", \"expected\": \"concurrent\", \"passed\": false}, {\"check\": \"unequal-sum concurrent writes\", \"actual\": \"after\", \"expected\": \"concurrent\", \"passed\": false}, {\"check\": \"strict causal extension\", \"actual\": \"before\", \"expected\": \"before\", \"passed\": true}, {\"check\": \"reverse causal extension\", \"actual\": \"after\", \"expected\": \"after\", \"passed\": true}, {\"check\": \"missing zero component\", \"actual\": \"equal\", \"expected\": \"equal\", \"passed\": true}, {\"check\": \"empty clocks\", \"actual\": \"equal\", \"expected\": \"equal\", \"passed\": true}, {\"check\": \"one replica progresses\", \"actual\": \"before\", \"expected\": \"before\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":36.438,"exit_code":1,"observations":[{"actual":"equal","check":"same-sum independent writes","expected":"concurrent","passed":false},{"actual":"after","check":"unequal-sum concurrent writes","expected":"concurrent","passed":false},{"actual":"before","check":"strict causal extension","expected":"before","passed":true},{"actual":"after","check":"reverse causal extension","expected":"after","passed":true},{"actual":"equal","check":"missing zero component","expected":"equal","passed":true},{"actual":"equal","check":"empty clocks","expected":"equal","passed":true},{"actual":"before","check":"one replica progresses","expected":"before","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"same-sum independent writes\", \"actual\": \"equal\", \"expected\": \"concurrent\", \"passed\": false}, {\"check\": \"unequal-sum concurrent writes\", \"actual\": \"after\", \"expected\": \"concurrent\", \"passed\": false}, {\"check\": \"strict causal extension\", \"actual\": \"before\", \"expected\": \"before\", \"passed\": true}, {\"check\": \"reverse causal extension\", \"actual\": \"after\", \"expected\": \"after\", \"passed\": true}, {\"check\": \"missing zero component\", \"actual\": \"equal\", \"expected\": \"equal\", \"passed\": true}, {\"check\": \"empty clocks\", \"actual\": \"equal\", \"expected\": \"equal\", \"passed\": true}, {\"check\": \"one replica progresses\", \"actual\": \"before\", \"expected\": \"before\", \"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."}}