Specification and verification of communicating systems with value passing

The present Thesis addresses the problem of specification and verification of communicating systems with value passing. We assume that such systems are described in the well-known Calculus of Communicating Systems, or rather, in its value passing version. As a specification language we propose an extension of the Modal mu-Calculus, a poly-modal first-order logic with recursion. For this logic we develop a proof system for verifying judgements of the form b⊢E:F where E is a sequential CCS term and b is a Boolean assumption about the value variables occurring free in E and F. Proofs conducted in this proof system follow the structure of the process term and the formula. This syntactic approach makes proofs easier to comprehend and machine assist. To avoid the introduction of global proof rules we adopt a technique of tagging fixpoint formulae with all relevant information needed for the discharge of reoccurring sequents. We provide such tagged formulae with a suitable semantics. The resulting proof system is shown to be sound in general and complete (relative to external reasoning about values) for a large class of sequential processes and logic formulae. We explore the idea of using tags to three different settings: value passing, extended sequents, and negative tagging.