Checking Timed Automata for Some Discretisable Duration Properties Checking Timed Automata for Some Discretisable Duration Properties

The mission of UNU/IIST is to assist developing countries in the application and development of software technology. UNU/IIST contributes through its programmatic activities: 1. advanced development projects in which software techniques supported by tools are applied, 2. research projects in which new techniques for software development are investigated, 3. curriculum development projects in which courses of software technology for universities in developing countries are developed, 4. courses which typically teach advanced software development techniques, 5. events in which conferences and workshops are organised or supported by UNU/IIST, and 6. dissemination, in which UNU/IIST regularly distributes to developing countries information on international progress of software technology. Fellows, who are young scientists and engineers from developing countries, are invited to actively participate in all these projects. By doing the projects they are trained. At present, the technical focus of UNU/IIST is on formal methods for software development. UNU/IIST is an internationally recognised center in the area of formal methods. However, no software technique is universally applicable. We are prepared to choose complementary techniques for our projects, if necessary. UNU/IIST produces a report series. Reports are either Research R , Technical T , Compendia C or Administrative A. They are records of UNU/IIST activities and research and development achievements. Many of the reports are also published in conference proceedings and journals. Abstract In this paper we propose a technique for checking a timed automaton w.r.t a class of discretisable duration properties. It is shown in the paper that if only integral constants are allowed in the time constraints of the timed automata, a linear duration property or an interstate duration property is satissed by a timed automaton if and only if it is satissed by all of the integral behaviours of the automaton. Therefore, checking linear duration properties or interstate duration properties can be done by using the integer time veriication techniques. Based on this, some algorithms are proposed. We also develop a technique for reducing the search-space for the proposed algorithms. This technique is specially suitable to our case, and can be applied to checking other duration properties as well.