Information Processing Letters

Managing Editor A. Tarlecki Inst. of Informatics, University of Warsaw, ul. Banacha Stefana 2, 02-097 Warszawa, Poland, Board of Editors F.Y.L. Chin Dept. of Computer Science and Information Systems, University of Hong Kong, Chow Yei Ching Building, Pokfulam Road, Pokfulam, Hong Kong, Hong Kong, G. Chockler IBM Research Haifa Laboratory, 31905 Haifa, Israel, M. Chrobak Dept. of Computer Science and Engineering, University of California at Riverside, Riverside, CA 92521, USA, B. Doerr Im Stadtwald - Gebäude 46.1, Max Planck Institut (MPI) für Informatik, D-66123 Saarbrücken, Germany, J.L. Fiadeiro Dept. of Computer Science, University of Leicester, University Road, Leicester, LE1 7RH, UK, T.-s. Hsu Inst. of Information Science 20, Academia Sinica, 128 Academia Road Section 2, 115-29 Taipei City, Taiwan, ROC, W.-L. Hsu Inst. of Information Science 20, Academia Sinica, 128 Academia Road Section 2, 115-29 Taipei City, Taiwan, ROC, L. Kowalik Inst. of Informatics, University of Warsaw, ul. Banacha Stefana 2, 02-097 Warszawa, Poland, A. Muscholl Lab. Bordelais de Recherche en Informatique, Institut Universitaire de Technologie, 351 Cours de la Liberation, 34405 Talence, France, D. Pointcheval Dept. d'Informatique, École Normale Supérieure, 45 rue D Ulm, 75230 Paris, France, V. Rijmen ESAT/SCD, bus 2446, Katholieke Universiteit Leuven, Kasteelpark Anenberg 10, 3001 Heverlee, Belgium, A. Sabelfeld Dept. of Computer Science & Engineering, Gothenburg University, Chalmers University of Technology, S-41296 Göteborg, Sweden, J. Torán Institut für Theoretische Informatik, Universität Ulm, D-89069 Ulm, Germany, R. Uehara School of Info. Science, Japan Advanced, Inst. Of Science Technology, Japan Advanced Institute of Science and Technology, Tatsunokuchi, 923-1292 Ishikawa, Japan, L. Viganò Fac. di Scienze Matematiche, Fisiche e Naturali, Università degli Studi di Verona, Strada le Grazie 15, I-37134 Verona, Italy, J. Wijsen Institut d'Informatique, Université de Mons, Place du Parc 20, B-7000 Mons, Belgium, X. Wu Dept. of Electrical and Computer Engineering, Dept. of Radiaiton Oncology, University of Iowa, 3318 Seamans Ctr. for Engineering Arts & Sciences, Iowa City, 52242, USA, J. Xu Dept. of Computer Science and Engineering, State University of New York (SUNY) at Buffalo, 201 Bell Hall, Buffalo, NY 14260-2000, USA, M. Yamashita Dept. of Computer Science, & Communication Engineering, Kyushu University, Hakozaki, 812-8581 Fukuoka, Japan, Advisory Editors D. Gries Dept. of Computer Science, Cornell University, Upson Hall, Ithaca, NY 14853-3801, USA, W.M. Turski Inst. of Informatics, University of Warsaw, ul. Banacha Stefana 2, 02-097 Warszawa, Poland