Hello Brian, Have you read Diskin's and Kadish's papers on CT and database theory? Here are a bunch of papers that all look pretty germane to what you are doing: http://citeseer.nj.nec.com/167037.html Regards, Vasili N Galchin __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices http://auctions.yahoo.com/