Compositional Proofs for Real-time Modular Systems

One common problem in applying formal methods to the analysis of realistic industrial-size systems is that these methods often do not scale well. In order to overcome such difficulty, formal languages and tools supporting modularization and compositionality must be realized and used. Under this respect, this thesis addresses the problem of designing techniques and tools to support the formal specification and verification of large modular real-time systems. The reference specification language for this analysis is the temporal metric TRIO. First, a mapping of the modular features of the TRIO language onto the language of the theorem prover PVS is designed. In connection with this, a number of automated proof strategies are designed to support the conduction of TRIO proofs in the PVS environment. Second, a rely/guarantee compositional framework for the language TRIO is discussed and a compositional proof rule is derived. This framework is also encoded in the PVS environment, so that it is practically usable. Finally, the benefits of adopting the proposed rely/guarantee compositional framework are discussed with the aid of working examples.