We propose two interpretations of rules, one re-active and the other proactive, corresponding to different kinds of interactions between the rules and the objects. Finally, we consider the problem of capturing domain specific knowledge within a general coordination framework, for which constraints offer a promising direction of research.
Constraints allow a nondeterministic evolution of the message exchanges among objects.
J.-M. Andreoli, H. Gallaire, and R. Pareschi. Rule-Based Object Coordination. Springer-Verlag, Berlin, 1995. The graph only includes citing articles where the year of publication is known.