Animating Formal Models in a Communicating Sequential Process Platform Ilias Sakellariou 1 , George Eleftherakis 2 , Ioannis Vlahavas 1 , and Petros Kefalas 2 1 Department of Informatics, Aristotle University of Thessaloniki, 54124 Thessaloniki Greece {iliass,vlahavas}@csd.auth.gr 2 Computer Science Department, City Liberal Studies, Affiliated College of the University of Sheffield, 13 Tsimiski Str., 54624, Thessaloniki, Greece. {eleftherakis,kefalas}@city.academic.gr Abstract. The X-machine formal method forms the basis for a specifi- cation/modeling language with a substantial potential value to software engineers. An X-machine is a more expressive and flexible state machine, capable of modeling both the dynamic and the static aspect of a system. Communicating X-machines provide a methodology for building com- municating systems out of existing stand-alone X-machines. However, for practically using the model in an real-world system development process, a tool for demonstrating and informally verifying the proper- ties of the modeled system is required. An ideal platform for efficiently implementing such a tool, should support, process oriented program- ming, efficient communication primitives and declarativeness. Cspcons is a distributed CLP platform that supports program execution over multiple independent sequential CLP processes that synchronize though message and event passing. The present paper demonstrates the applica- bility of the Cspcons programming model to the implementation of a communicating X-machine animator tool that will act as the basis for an extended set of tools that will support the formal mathematical analysis of the specified X-machine models. Keywords: Formal Methods, Animator Tool, Logic Programming 1 Introduction The extensive use of computers in all aspects of every day life and industry and the fact that the required control functions increasingly demand more complex software, necessitate the need for research toward the improvement of the com- puterised systems development process. The application of formal methods to the development process of critical systems appears to be a promising solution [1]. One of the main problems in such a development process is ensuring correct- ness of system specifications. This issue is of vital importance, since errors in the specification have a significant impact to the project’s success. Due to the