It was during the MODNET Conference on Model Theory in An-
talya, November 2–11, 2006, that I placed the first chapter of the
book on the Internet. MODNET (Marie Curie Research Training
Network in Model Theory and Applications) is funded by the Euro-
pean Commission under contract no. MRTN-CT-2004-512234.
In July 2007 and July 2008 I enjoyed the hospitality of Mathe-
matical Village in S ¸irince, Turkey, built and run by Ali Nesin.
I started writing this book in Caf´ e de Flore, Paris—an extreme
case of vanity publishing! Since then, I continued my work in
many fine establishments, among them Airbr¨ au, das Brauhaus im
Flughafen in Munich, Cafe del Turco in Antalya, L’authre Bistro on
rue des Ecoles, and Caf´ e des Arts on place de la Contrescarpe in
Paris—I thank them all.
July 10, 2009