This might be of some help, circa Haskell 1.2, SetMap.hs - sets and maps in Haskell Author: Nick North ftp://ftp.cs.chalmers.se/pub/haskell/library/SetMap.hs Chris ===== Christopher Milton cmiltonperl@yahoo.com __________________________________________________ Do you Yahoo!? Yahoo! Web Hosting - Let the expert host your site http://webhosting.yahoo.com