An Approach to Concurrent Semantics Using Complete Traces

In this thesis we address the problem of how to give acceptable formal semantics for concurrent programming languages, that is, how to give a precise mathematical formulation of what programs in various such languages mean. We take a broad view of what constitutes a programining language - for example, notations that describe digital circuits or Petri nets we consider programming languages, as well as notations that describe systems of concurrent processes interacting via shared variables or message-passing. It is important that we have a formal semantics for any programming language we use, for the following reasons: 1. It is needed in order to precisely define the language. 2. It is needed to provide some basis for deciding the correctness of implementations of the language. 3. IL is iieeded to provide a foundation for methods of analyzing and reasoning about the behavior of programs in the language. In this thesis we shall not concern ourselves with 2. and 3. above, but shall concentrate on the prob lem of specifying the semantics of concurrent programming languages and showing the semantics to be acceptable' in some sense. Sponsored in part by DARPA.