An action based framework for verifying logical and behavioural properties of concurrent systems

A system is described which supports proofs of both behavioural and logical properties of concurrent systems; these are specified by means of a process algebra and its associated logics. The logic is an action based version of the branching time logic CTL which we call ACTL; it is interpreted over transition labelled structures while CTL is interpreted over state labelled ones. The core of the system are two existing tools, AUTO and EMC. The first builds the labelled transition system corresponding to a term of a process algebra and permits proof of equivalence and simplification of terms, while the second checks validity of CTL logical formulae. The integration is realized by means of two translation functions from the action based branching time logic ACTL to CTL and from transition-labelled to state-labelled structures. The correctness of the integration is guaranteed by the proof that the two functions when coupled preserve satisfiability of logical formulae

Interaction Categories and the Foundations of Typed Concurrent Programming

We propose Interaction Categories as a new paradigm for the semantics of functional and concurrent computation. Interaction categories have specifications as objects, processes as morphisms, and interaction as composition. We introduce two key examples of interaction categories for concurrent computation and indicate how a general axiomatisation can be developed. The upshot of our approach is that traditional process calculus is reconstituted in functorial form, and integrated with type theory and functional programming

CCS without tau's

The main point of this paper is that one can develop an adequate version of CCS which does not use the special combinator tau for internal actions. Instead, the choice operator +, whose semantics is somewhat unclear, is replaced by two new choice operators oplus and [], representing internal and external nondeterminism respectively. The operational semantics of the resulting language is simpler and the definition of testing preorders is significantly cleaner. The essential features of the original calculus are kept; this is shown by defining a translation from CCS to the new language which preserves testing preorders