An extension of the linear complementarity problem (LCP) of mathematical pr
ogramming is the so-called rational complementarity problem (RCP). This pro
blem occurs if complementarity conditions are imposed on input and output v
ariables of linear dynamical input/state/output systems. The resulting dyna
mical systems are called linear complementarity systems. Since the RCP is c
rucial both in issues concerning existence and uniqueness of solutions to c
omplementarity systems and in time simulation of complementarity systems, i
t is worthwhile to consider existence and uniqueness questions of solutions
to the RCP. In this paper necessary and sufficient conditions are presente
d guaranteeing existence and uniqueness of solutions to the RCP in terms of
corresponding LCPs. Using these results and proving that the corresponding
LCPs have certain properties, we can show uniqueness and existence of solu
tions to linear mechanical systems with unilateral constraints, electrical
networks with diodes, and linear dynamical systems subject to relays and/or
Coulomb friction. (C) 1999 Elsevier Science Inc. All rights reserved.