Behavior Trees as executable representation of Milner Calculus notations

The efforts that go into setting up stable, efficient, fault-tolerant Multi-Agent Systems are twofold: Modelling and designing agent interactions with both environment and other agents; and transfering the model into an actual executable implementation of the system. For formal modeling, notations in process calculi, such as Milner’s Calculus for Communicating Systems (CCS), have shown to be helpful, as they allow for formal model checking of the system before implementation. Typically, translating from such notations to an executable counterpart comes with pitfalls, as constraints and limitations set by the chosen programming language or software framework make a one-to-one mapping from the formal expression to executable code difficult. In this paper, we for this investigate the similarities between formal expressions in CCS, and executable behavior trees as agent programs. Our study confirms that a semantic preserving mapping between both exist, and we demonstrate how to exploit these similarities to transfer CCS expressions to semantically equivalent, executable agent programs.