English text.
ACKNOWLEDGMENTS
I thank Dr. Olivier Simon for making himself available for answering my questions and giving me many examples. I must thank him twice because he had all the patience in the world for me. He is almost the coauthor of this book.
I thank Sylvain Auclair, Martín Rincón Botero and Justin Gagnon, who helped me a lot.
I also thank Cale Short and Kate Moss for revising few parts of the English text.
