  The use of multivalued controls derived from a special maximal monotone
operator are studied in this note. Starting with a strictly passive linear
system (with possible parametric uncertainty and external disturbances) a
multivalued control law is derived, ensuring regulation of the output to a
desired value. The methodology used falls in a passivity-based control context,
where we study how the multivalued control affects the dissipation equation of
the closed-loop system, from which we derive its robustness properties.
Finally, some numerical examples together with implementation issues are
presented to support the main result.
