“…Variational inequalities of the form (1.2) occur, for example, when considering the variational formulation of second order partial differential equations with boundary conditions of Signorini type, e.g., [12,19,24], or when considering contact problems in elasticity without friction, e.g., [4,7,8,11]. Other applications involve Dirichlet boundary control problems with control constraints, e.g., [17,22].…”