Page 9 -

viii Preface

and tables contained in the book. Readers are free touse this mate-
rial for lectures and presentations, butmust ask forpermissionif they
want to include it in their ownpublications.Forall questions, please
contact me at www.lps.ens.fr/ krauth.(This website will also keep a
list of misprints.) Readers ofthe bookmaywant to get in contact with
each other, and some may feel challenged to translate the pseudocode
programs intoone ofthe popular computer languages;I will be happy
to assist initiatives in this direction, and to announce them onthe above
website.