René David Karim Nour Arithmetical Proofs of Strong Normalization Results for the Symmetric lambda-µ-Calculus. 162-178 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3461&spage=162 2005 conf/tlca/2005 TLCA db/conf/tlca/tlca2005.html#DavidN05