Specification of asynchronous communicating systems (SACS).

This paper presents the Specification of Asynchronous Communication System (SACS), a formal notation that is used to
specify an asynchronous message passing system which uses point-to-point communication. SACS is a modified version
of a synchronous variant of the Calculus of Communicating System (CCS) known as the Synchronous Calculus of
Communicating Systems (SCCS). The basic aim of this technique is to separate communication from computation so that
these two activities can proceed independently as far as possible. Except for the asynchronous nature, the communication
is assumed to be point-to-point as in SCCS. These design techniques allow the programmer to develop programs that are
virtually free of livelock and deadlock conditions. SACS complies with four design rules which emerged from our
experience in developing distributed applications using a message passing language called Language for Implementing
Parallel/distributed Systems (LIPS).