Jesse D. Bingham Alan J. Hu Empirically Efficient Verification for a Class of Infinite-State Systems. 77-92 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3440&spage=77 2005 conf/tacas/2005 TACAS db/conf/tacas/tacas2005.html#BinghamH05