Analysis of a mixed formulation of a bilateral obstacle problem

In this paper we present a reformulation of a bilateral obstacle problem as a mixed formulation problem based on subdifferential of a continuous function of which the subdifferential can characterize the non-contact domain. Then we present the analysis of the discrete problem. We prove the convergence of the approximate solution to the exact one and we provide an error estimate. This formulation was established in an abstract way, then the theoretical results was applied to a bilateral obstacle problem.