A Specification Structure for Deadlock-Freedom of Synchronous Processes

Many diierent notions of \program property", and many diierent methods of verifying such properties, arise naturally in programming. We present a general framework of Speciication Structures for combining diierent notions and methods in a coherent fashion. We then apply the idea of speciication structures to concurrency in the setting of Interaction Categories. As a speciic example, a certain speciica-tion structure deened over the interaction category SProc yields a new category SProc D in which morphisms are deadlock-free concurrent processes and composition is process interaction. SProc D is obtained from SProc by adding speciication information to the objects which is strong enough to guarantee deadlock-freedom. The main technical contribution is to show that this can be done in a way which is preserved by composition. The methods used to achieve this can be seen as a semantic analogue of those used to prove strong normalization in classical linear logic.