A family of Least-Change Secant-Update methods for solving nonlinear comple
mentarity problems based on nonsmooth systems of equations is introduced. L
ocal and superlinear convergence results for the algorithms are proved. Two
different reformulations of the nonlinear complementarity problem as a non
smooth system are compared, both from the theoretical and the practical poi
nt of view. A global algorithm for solving the nonlinear complementarity pr
oblem which uses the algorithms introduced here is also presented. Some num
erical experiments show a good performance of this algorithm. (C) 1999 Else
vier Science B.V. and IMACS. All rights reserved.