Lecture Notes in Computer Science Commenced Publication in 1973 Founding and Former Series Editors: Gerhard Goos, Juris Hartmanis, and Jan van Leeuwen Editorial Board David Hutchison Lancaster University, UK Takeo Kanade Carnegie Mellon University, Pittsburgh, PA, USA Josef Kittler University of Surrey, Guildford, UK Jon M. Kleinberg Cornell University, Ithaca, NY, USA Friedemann Mattern ETH Zurich, Switzerland John C. Mitchell Stanford University, CA, USA Moni Naor Weizmann Institute of Science, Rehovot, Israel Oscar Nierstrasz University of Bern, Switzerland C. Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen University of Dortmund, Germany Madhu Sudan Massachusetts Institute of Technology, MA, USA Demetri Terzopoulos New York University, NY, USA Doug Tygar University of California, Berkeley, CA, USA Moshe Y. Vardi Rice University, Houston, TX, USA Gerhard Weikum Max-Planck Institute of Computer Science, Saarbruecken, Germany 3831 Jiˇrí Wiedermann Gerard Tel Jaroslav Pokorný Mária Bieliková Július Štuller (Eds.) SOFSEM 2006: Theory and Practice of Computer Science 32nd Conference on Current Trends in Theory and Practice of Computer Science Mˇeˇrín, Czech Republic, January 21-27, 2006 Proceedings 13 Volume Editors Jiˇrí Wiedermann Július Štuller Academy of Sciences of the Czech Republic Institute of Computer Science Pod Vodárenskou vˇeží 2, 182 07 Prague 8, Czech Republic E-mail: {jiri.wiedermann,stuller}@cs.cas.cz Gerard Tel Universiteit Utrecht Department of Information and Computing Sciences Centrumgebouw Noord, office A308, Padualaan 14, De Uithof 3584CH Utrecht, The Netherlands E-mail:
[email protected] Jaroslav Pokorný Charles University, Faculty of Mathematics and Physics Malostranské nám. 25, 118 00 Prague 1, Czech Republic E-mail:
[email protected] Mária Bieliková Slovak University of Technology in Bratislava Institute of Informatics and Software Engineering Faculty of Informatics and Information Technologies Ilkoviˇcova 3, 842 16 Bratislava 4, Slovak Republic E-mail:
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