“…All these papers consider problems with no unilateral constraint (that is, ϕ = 0) and the reaction term F is single-valued. Variational inequalities (that is, problems where ϕ is the indicator function of a closed, convex set), were investigated by Arcoya, Carmona and Martinez Aparicio [2], Matzeu and Servadei [15], Mokrane and Murat [17]. All have single valued source term.…”