Guillaume Feuillade Thomas Genet Valérie Viet Triem Tong Reachability Analysis over Term Rewriting Systems. 341-383 2004 33 J. Autom. Reasoning 3-4 http://www.springerlink.com/index/10.1007/s10817-004-6246-0 db/journals/jar/jar33.html#FeuilladeGT04