An Abstract Interpretation Framework for Verification of Timed Concurrent Constraint Languages

The Timed Concurrent Constrain programming (tccp in short) is a concurrent logic language obtained by extending the cc paradigm with the notion of time and a suitable mechanism to model time-outs and preemptions. Thanks to these features, tccp is a suitable language to model both concurrent and reactive systems. The existing formal techniques for the verification of tccp are based on model checking. Given a program P and a temporal formula φ, model checking essentially works by browsing the structure of some form of model M (which represents the behavior of P ) to check if φ is valid. This implies that the model M has to be built and, especially in presence of concurrency, this model is quite huge. This problem is well known in the literature and it is called state-explosion problem. The core of my research is the definition of a semantic framework for tccp for the formal verification of complex concurrent and reactive systems by using abstract interpretation theory. This approach is based on the definition of a concrete semantics for tccp which is suitable to be approximated by using standard abstract interpretation results. In this way, it is possible to define debugging and verification tools for tccp without the burden of modeling the system first. Thus, abstract interpretation becomes a valid alternative to model checking, since it overcomes the state-explosion problem.