Hi all, <http://www.nature.com/news/2004/041213/full/041213-3.html> which is linked from the front page of Nature <http://www.nature.com/> mentions Olivier Danvy. The original paper about it is found from: <http://www.brics.dk/~danvy/Giles04PNASacknowledgements.pdf> where I see many PL researchers including Matthias. -- Kenichi Asai