John Longley Randy Pollack Reasoning About CBV Functional Programs in Isabelle/HOL. 201-216 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3223&spage=201 2004 conf/tphol/2004 TPHOLs db/conf/tphol/tphol2004.html#LongleyP04