Abstract: We propose a formal framework for the specification of
the behavior of a system of agents, as well as those of the constituting
agents. This framework allows us to model each agent-s effectoric
capability including its interactions with the other agents. We also
provide an algorithm based on Milner-s "observation equivalence" to
derive an agent-s perception of its task domain situations from its
effectoric capability, and use "system computations" to model the
coordinated efforts of the agents in the system . Formal definitions
of the concept of "behavior equivalence" of two agents and that of
system computations equivalence for an agent are also provided.