The seventeenth session of the Petrovskii seminar and the Moscow Mathematical Society opened on 24 January 1995 in the principal building of Moscow University in the Vorob'ev hills. More than 200 people took part in the work of the session, and heard and discussed more than 180 talks. About half of them were given by scholars from other towns; the authors of more than 20 talks were representatives from foreign countries near and far. The subjects of the talks covered a wide range of problems in the theory of partial differential equations, mathematical physics, ordinary differential equations, dynamical systems, function theory, functional analysis, probability theory, topology, and computational mathematics.