Elliptic problems with discontinuities

In this paper we prove two existence theorems for elliptic problems with discontinuities. The first one is a noncoercive Dirichlet problem and the second one is a Neumann problem. We do not use the method of upper and lower solutions. For Neumann problems we assume that <f>f</f> is nondecreasing. We use the critical point theory for locally Lipschitz functionals. [Copyright &y& Elsevier]