Translation between S/r and Promela

S/R and Promela are two concurrent programming languages used in nite state automated veriication of communication protocols. The semantics of S/R supports synchronous parallel composition, while semantics of Promela supports an interleaving parallel composition of processes. Because of the diierences in the execution model, the veriication tools available for the models written in these languages are optimized diierently. SPIN, a veriication tool for models written in Promela, uses partial order reduction reductions based upon commutativity of interleaving to combat the state explosion problem due to the amount of concurrency in concurrent models. COSPAN, a tool used largely for hardware veriication for models written in S/R, ooers implicit enumeration and automatic reduction of the speciication with respect to the properties to be veriied. Because of such diierences in the techniques used for combating the practical problems faced in veriication of protocols, it may be desirable to translate the protocols written in one language into the other. For example, if there were a Promela model for which veriication were intractable in spite of the partial order reductions in SPIN, there is a possibility that the reduction algorithms or implicit enumeration algorithms in COSPAN may be tractable. Conversely, an interleaving model speciied in S/R may be executed more eeciently in SPIN. This document describes two translators, s2p and p2s, to translate S/R into Promela and Promela to S/R respectively. The eeecitiveness of the translators is illustrated with the aid of two examples.