Duke University / School of Computer Science / University of Ljubljana / New York University / New York / Durham NC / IMFM / National Science Foundation / Slovenian Research Agency / Department of Computer Science / U.S.-Israeli Binational Science Foundation / Universitat de Girona / Institut d’Inform`atica / Department of Mathematics / Spanish Ministry of Education / Israel Science Fund / MINERVA Center for Geometry / Courant Institute of Mathematical Sciences / Tel Aviv University / Tel Aviv / /