In this paper we investigate a new technique to determine whether an open continuous system behaves correctly for all admissible
input signals. This technique is based on a discretization of the set of possible input signals, and on storing neighborhoods
of points reachable by trajectories induced by those signals. Alternatively, this technique, inspired by automata theory,
can be seen as an attempt to make simulation a more systematic activity by finding a small set of input signals such that
the behaviors they induce “cover” the whole reachable state space.