On the Identification of Zero Variablesin

We consider column suucient linear complementarity problems and study the problem of identifying those variables that are zero at a solution. To this end we propose a new, computationally inexpensive technique that is based on growth functions. We analyze in detail the theoretical properties of the identiication technique and test it numerically. The identiication technique is particularly suited to interior-point methods but can be applied to a wider class of methods.