On the Chromatic Number of Graphs

In this paper, the property of a function to be without exceptional family of elements (EFE) is investigated. We show that, for a pseudomonotone operator, the solvability of a complementarity problem is equivalent to the property of the function to be without EFE. Finally, we study the strict feasibility of a complementarity problem making use of the Leray-Schauder alternative and the notion of EFE.