Manindra Agrawal P. S. Thiagarajan The Discrete Time Behavior of Lazy Linear Hybrid Automata. 55-69 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3414&spage=55 2005 conf/hybrid/2005 HSCC db/conf/hybrid/hscc2005.html#AgrawalT05