Lectures: B. Malgrange: Operatori differenziali.- J. Mikusinski: Une introduction elementaire a la theorie des distributions de plusieurs variables.- L. Schwartz: I. Trasformata di Fourier delle distribuzioni; II. Spazi di Hilbert e nuclei associati.- Seminars: J.B. Diaz: Solutions of the singular Cauchy problem for a singular system of partial differential equations in the mathematical theory of dynamical elasticity.- J. Gobert: Un cas critique du probleme de Dirichlet-Neumann.- J.L. Lions: Espaces dinterpolation. Espaces de moyenne.- J. Sebastiao e Silva: Sur laxiomatique des distributions et ses possibles modeles.- S. Zaidman: Distribuzioni quasi-periodiche e applicazioni.

C. Baiocchi: Problemes a frontiere libre lies a des questions d hydraulique.- Ch. Castaing: Integrales convexes duales.- G. Duvaut: Etude de problemes unilateraux en mecanique par des methodes variationnelles.- D. Kinderlehrer: Remarks about the free boundaries occurring in variational inequalities.- H. Lanchon: Torsion elastoplastique d arbres cylindriques: problemes ouverts.- J.M. Lasry: Dualite en calcul des variations.- J.J. Moreau: On unilateral constraints, friction and plasticity.- B. Nayroles: Point de vue algebrique. Convexite et integrantes convexes en mecanique des solides.- W. Noll: On certain convex sets of measures and phases of reacting mixtures.- W. Velte: On complementary variational inequalities.

During the fifties, one of the authors, G. Stampacchia, had prepared some lecture notes on ordinary differential equations for a course in ad analysis. These remained for a long time unused because he was no vanced longer very interested in the study of such equations. We now see, though, that numerous applications to biology, chemistry, economics, and medicine have recently been added to the traditional ones in mechanics; also, there has been in these last years a reemergence of interest in nonlinear analy sis, of which the theory of ordinary differential euqations is one of the principal sources of methods and problems. Hence the idea to write a book. Our text, based on the old notes and experience gained in many courses, seminars, and conferences, both in Italy and abroad, aims to give a simple and rapid introduction to the various themes, problems, and methods of the theory of ordinary differential equations. The book has been conceived in such a way so that even the reader who has merely had a first course in calculus may be able to study it and to obtain a panoramic vision of the theory. We have tried to avoid abstract formalism, preferring instead a discursive style, which should make the book accessible to engineers and physicists without specific preparation in modern mathematics. For students of mathematics, it pro vides motivation for the subject of more advanced analysis courses."