Title: The Morse-Sard theorem, generalized Luzin property and level sets for
       Sobolev functions

Abstract:
Many classical results from multivariate calculus can be generalized to suitable
Sobolev functions that need not even be everywhere differentiable. In this talk
we discuss some new results that have been obtained in joint work with 
Jean Bourgain (Princeton) and Mikhail Korobkov (Novosibirsk).