In-Ho Moon Carl Pixley Non-miter-based Combinational Equivalence Checking by Comparing BDDs with Different Variable Orders. 144-158 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3312&spage=144 2004 conf/fmcad/2004 FMCAD db/conf/fmcad/fmcad2004.html#MoonP04