Abhay Vardhan Koushik Sen Mahesh Viswanathan Gul Agha Learning to Verify Safety Properties. 274-289 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3308&spage=274 2004 conf/icfem/2004 ICFEM db/conf/icfem/icfem2004.html#VardhanSVA04