Model checking concurrent and real-time systems : the PAT approach

Ph.DDOCTOR OF PHILOSOPH

Combining type checking with model checking for system verification

Type checking is widely used in mainstream programming languages to detect programming errors at compile time. Model checking is gaining popularity as an automated technique for systematically analyzing behaviors of systems. My research focuses on combining these two software verification techniques synergically into one platform for the creation of correct models for software designs. This thesis describes two modeling languages ATS/PML and ATS/Veri that inherit the advanced type system from an existing programming language ATS, in which both dependent types of Dependent ML style and linear types are supported. A detailed discussion is given for the usage of advanced types to detect modeling errors at the stage of model construction. Going further, various modeling primitives with well-designed types are introduced into my modeling languages to facilitate a synergic combination of type checking with model checking. The semantics of ATS/PML is designed to be directly rooted in a well-known modeling language PROMELA. Rules for translation from ATS/PML to PROMELA are designed and a compiler is developed accordingly so that the SPIN model checker can be readily employed to perform checking on models constructed in ATS/PML. ATS/Veri is designed to be a modeling language, which allows a programmer to construct models for real-world multi-threaded software applications in the same way as writing a functional program with support for synchronization, communication, and scheduling among threads. Semantics of ATS/Veri is formally defined for the development of corresponding model checkers and a compiler is built to translate ATS/Veri into CSP# and exploit the state-of-the-art verification platform PAT for model checking ATS/Veri models. The correctness of such a transformational approach is illustrated based on the semantics of ATS/Veri and CSP#. In summary, the primary contribution of this thesis lies in the creation of a family of modeling languages with highly expressive types for modeling concurrent software systems as well as the related platform supporting verification via model checking. As such, we can combine type checking and model checking synergically to ensure software correctness with high confidence

Towards the verification of RAISE specifications through Model Checking

Ensuring the correctness of a given software component has become a crucial aspect in Software Engineering and the Model Checking technique provides a fully automated way to achieve this goal. In particular, the usage of Model Checking in formal languages has been reinforced in the last decades because the specifications themselves provide an abstraction of the problem under study (whether created by abstraction from the software or by hand) and the properties validated at the specification level can be warrantied to be preserved until implementation. In this paper we focus on the main issues for adding Model Checking functionalities to the RAISE specification language and present the most important characteristics of our current approach for doing so. An outline of the main issues and problems faced in the process and possible ways to solve them are also presented.Eje: Ingeniería de software y base de datosRed de Universidades con Carreras en Informática (RedUNCI

Comparative Studies, Formal Semantics and PVS Encoding of CSP#

Ph.DDOCTOR OF PHILOSOPH

Formal methods to improve public administration business processes

Starting from late 90’s the public administration has started to employ a quite relevant amount of its budget in develop ing ICT solutions to better deliver services to citizens. In spite of this effort many statistics show that the mere availability of ICT based services does not guarantee per se their usage. Citizens have continued to largely access services through “traditional” means. In our study we suggest that the highlighted situation is partly due to the fact that relevant domain dependent requirements, mainly related to the delivery process of e-government digital services, are often ignored in the development of e-government solutions. We provide here a domain related quality framework and encoded it in a set of formal statements, so that we can apply automatic verification techniques to assess and improve ICT solutions adopted by public administrations. The paper discusses both the defined quality framework and the tool chain we developed to enable automatic assessment of ICT solutions. The tool chain is based on a denotational mapping of business process modeling notation elements into process algebraic descriptions and to the encoding of quality requirements in linear temporal logic formulas. The resulting approach has been applied to real case studies with encouraging results

Towards the verification of RAISE specifications through Model Checking

Ensuring the correctness of a given software component has become a crucial aspect in Software Engineering and the Model Checking technique provides a fully automated way to achieve this goal. In particular, the usage of Model Checking in formal languages has been reinforced in the last decades because the specifications themselves provide an abstraction of the problem under study (whether created by abstraction from the software or by hand) and the properties validated at the specification level can be warrantied to be preserved until implementation. In this paper we focus on the main issues for adding Model Checking functionalities to the RAISE specification language and present the most important characteristics of our current approach for doing so. An outline of the main issues and problems faced in the process and possible ways to solve them are also presented.Eje: Ingeniería de software y base de datosRed de Universidades con Carreras en Informática (RedUNCI

Enhancing State Space Reduction Methods for Model Checking

Ph.DDOCTOR OF PHILOSOPH

Transformations between CSP# and C#

Ph.DDOCTOR OF PHILOSOPH