> http://www.cs/kuleuven.be/~steveno/files/VanLanduytasat07.pdf I guess you meant: http://www.cs.kuleuven.be/~steveno/files/VanLanduytasat07.pdf Cheers, Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.