A Fully Parallel Calculus of Synchronizing Processes

We propose a fully parallel calculus of synchronizing processes. The calculus was deeply inspired by LOTOS, of which it inherits multi-party synchronization in process parallel composition. On the other hand, its semantics is not interleaving whereas LOTOS one is. The model we propose is somehow in between Milner's SCCS and ASCCS in that independent actions are performed simultaneously, whereas synchronization is achieved by means of delay. Also, delay is controlled in the sense that no process can delay an action if the environment allows that action to be performed. The calculus we propose here was originally designed as a rst step towards a probabilistic one. Nevertheless we think that the pure version of the calculus has some features which are interesting on their own. As an example we use it to describe a quite simple system which may be thought of as a possible fault tolerant architecture for a hardware component. We also provide a set of equational laws based on a notion of strong bisimu-lation.