Cypher pre-v5 fraud ring detection query

query_v4.cypher

// Produce any 2-to-6-hop-long path
MATCH path=(a:Account)-[rel:TRANSACTION*2..6]->(a)
// Then filter to keep only
// 	- non-node-repeating paths (using some APOC magic)
WHERE size(apoc.coll.toSet(nodes(path))) = size(nodes(path)) - 1
// 	- and, at each step…
AND ALL(idx in range(0, size(rel)-2)
  // … date-consistent
  WHERE (rel[idx]).date < (rel[idx+1]).date
  // … and 20%-rule compliant paths
  AND tx[idx].amount >= tx[idx+1].amount >= 0.80 * tx[idx].amount
)
// Return all paths
RETURN path