Although it has changed considerably in both coverage and length, this book originated from lecture courses at the Ecole Polytechnique. It is useful to re mind non-Prench readers of the special place this institution occupies in our education system, as it has few features in common with institutes with a similar name in other parts of the world. In fact, its programme corresponds to the intermediate years at a university, while the level of the students is particularly high owing to their strict selection through entrance examina tions. The courses put a stress on giving foundations with a...