The subject matter of this paper falls into the area of process algebra, a well-known algebraic theoretic framework for modeling and reasoning about concurrent and communicating systems. In particular, this paper presents a class of models called symbolic transition graphs with look ahead (STGLA). STGLAs are finite labeled graphs, and can capture the infinite behaviors of value passing process algebras.

STGLAs are based on symbolic transition graphs with assignments (STGAs), earlier proposed for the finite modeling of value passing algebras. It is argued that STGLAs are more powerful and natural than STGAs. A fragment of the value passing extension of Milner’s calculus of communicating systems is given semantics using STGLAs. For some notions of compactness, it is shown that the STGLAs for this fragment are compact.

The paper is reasonably well written, and easy to read. The proof could have been relegated to an appendix, so that the flow of the results would be smoother. The paper is narrow in scope, and will be useful for people interested in process algebras. The notion of compactness is intuitively clear, but is defined rather informally.