Robert Nieuwenhuis Albert Oliveras Congruence Closure with Integer Offsets. 78-90 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2850&spage=78 2003 conf/lpar/2003 LPAR db/conf/lpar/lpar2003.html#NieuwenhuisO03