Peter Dybjer Qiao Haiyan Makoto Takeyama Combining Testing and Proving in Dependent Type Theory. 188-203 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2758&spage=188 2003 conf/tphol/2003 TPHOLs db/conf/tphol/tphol2003.html#DybjerHT03