The study of complementarity problems is now an interesting
mathematical subject with many applications in optimization,
game theory, stochastic optimal control, engineering,
economics etc.
This subject has deep relations with important domains of
fundamental mathematics such as fixed point theory, ordered
spaces, nonlinear analysis, topological degree, the study of
variational inequalities and also with mathematical modeling
and numerical analysis.
Researchers and graduate students interested in mathematical
modeling or nonlinear analysis will find here interesting
and fascinating results.

Preliminaries and defintions of principal complementarity problems.- Models and applications.- Equivalences.- Exitence theorems.- The order complementarity problem.- The implicit complementarity problem.- Isotone projection cones and complementarity.- Topics on complementarity problems.- Errata.