Jürgen Giesl Armin Kühnemann Janis Voigtländer Deaccumulation - Improving Provability. 146-160 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2896&spage=146 2003 conf/asian/2003 ASIAN db/conf/asian/asian2003.html#GieslKV03