Undecidability Results for Deterministic Communicating Sequential Processes

We study the subset of the communicating sequential processes formalism in which processes are described in terms of recursive equations that use only constant processes, deterministic choice, parallel composition, and sequential composition. Even with this limited version, the formalism is powerful enough to model a Turing machine, so that a number of important problems such as boundedness, deadlock, and reachability are undecidable. © 1990 IEEE