Timed Modal Specification - Theory and Tools

. In this paper we present the theory of Timed Modal Specifications (TMS) together with its implementation, the tool Epsilon. TMS and Epsilon are timed extensions of respectively Modal Specifications [7, 9] and the Tav system [6, 4]. Also, the theory of TMS is an extension of real--timed process calculi with the specific aim of allowing loose or partial specifications. This allows us to define a notion of refinement, generalizing in a natural way the classical notion of bisimulation. 1 Introduction In this paper we present the theory of Timed Modal Specifications (TMS) together with its implementation, Epsilon. TMS and Epsilon are timed extensions of respectively Modal Specifications [7, 5, 9] and the Tav system [6, 4]. During the last few years various process calculi have been extended to include real--time in order to handle quantitative aspects of real--time systems. We mention the calculi defined in [14] and the ones defined in [12] and [3]. Common to these real--time calcul..

Timed Modal Specification -- Theory and Tools

In this paper we present the theory of Timed Modal Specifications (TMS) together with its implementation, the tool Epsilon. TMS and Epsilon are timed extensions of respectively Modal Specifications [Lar90, LT88] and the Tav system [GLZ89, BLS92].The theory of TMS is an extension of real-timed process calculi with the specific aim of allowing loose or partial specifications. Looseness of specifications allows implementation details to be left out, thus allowing several and varying implementations. We achieve looseness of specifications by introducing two modalities to transitions of specifications: a may and a must modality. This allows us to define a notion of refinement, generalizing in a natural way the classical notion of bisimulation. Intuitively, the more must-transitions and the fewer may-transitions a specification has, the finer it is. Also, we introduce notions of refinements abstracting from time and/or internal computation.TMS specifications may be combined with respect to the constructs of the real-time calculus [Wan90]. "Time-sensitive" notions of refinements that are preserved by these constructs are defined, thus enabling compositional verification. Epsilon provides automatic tools for verifying refinements. We apply Epsilon to a compositional verification of a train crossing example

Algorithmic Analysis of Programs with Well Quasi-Ordered Domains

Over the last few years there has been an increasing research effort directed towards the automatic verification of infinite state systems. This paper is concerned with identifying general mathematical Supported in part by the Swedish Board for Industrial and Technical Development (NUTEK) and by the Swedish Research Council for Engineering Sciences (TFR). The work of the second author has been partially supported by Grant No. 93-596 from Latvian Council of Science. The work of the fourth author has been partially supported by the National Science Council, TAIWAN (R.O.C). structures which can serve as sufficient conditions for achieving decidability. We present decidability results for a class of systems (called well-structured systems), which consist of a finite control part operating on an infinite data domain. The results assume that the data domain is equipped with a preorder which is a well quasi-ordering, such that the transition relation is "monotonic" (is a simulation) wit..

General Decidability Theorems for Infinite-State Systems

) Parosh Aziz Abdulla Uppsala University K¯arlis Cer¯ans University of Latvia Bengt Jonsson Uppsala University Yih-Kuen Tsay National Taiwan University Abstract Over the last few years there has been an increasing research effort directed towards the automatic verification of infinite state systems. For different classes of such systems (e.g., hybrid automata, data-independent systems, relational automata, Petri nets, and lossy channel systems) this research has resulted in numerous highly nontrivial algorithms. As the interest in this area increases, it will be important to extract common principles that underly these and related results. This paper is concerned with identifying general mathematical structures which could serve as sufficient conditions for achieving decidability. We present decidability results for systems which consist of a finite control part operating on an infinite data domain. The data domain is equipped with a well-ordered and well-founded preorder such tha..