Aclt F G Aclt Aclt Aclt Respect Respect Expressive Power of the Reaction Specication Language

Multi-agent systems, Coordination, Tuple Spaces, Petri Nets, Programmable Coordination Media, Turing equivalence The notion of as a shared communication device whose behaviour can be de ned according to the global system needs has indeed an impact over the design of multi-component software system. In fact, it allows coordination systems to be organised around a high-level inter-component interaction protocol, while the low-level details are delegated to properly programmed communication abstractions. This leads to a shift of (part of) the computational charge of a multi-component system from the communicating components (agents) to the communication device, and raises the issue of the expressive power of a programmable coordination medium. As an example, this paper discusses the case of , the rst-order logic lan-