An Implementation of Sdl 92 Communication Semantics 1

The paper describes an abstract implementation of SDL communication semantics in the larger context of a design of SDL 92 simulation and veriication tools. SDL signal exchange involves routing for signal traac that allows for nondeterminism in communication path selection. The communication path selected may additionally be subject to a path constraint using SDL's via construct. We describe rst a straightforward decomposition of an SDL program in a CSP like process algebra called ERPAL, and then reduce it to the nal ERPAL model by eliminating the no-delay channels, signal routes and gates. The reduction involved simpliies the implementation and yet preserves the intended SDL semantics.