A state space generation tool for LOTOS specifications: Licenciate thesis

A concurrent system can be represented as a model consisting of all reachable states and the atomic discrete actions between them. The goal of state space generation is to produce a model of this kind, known as a state space or labelled transition system, to represent a given system description model. We present here a tool for the state space generation of concurrent systems descriptions and the input language for this tool. The tool is a part of the ARA Tools environment for advanced reachability analysis of concurrent systems, and its input language, ARA LOTOS, is a variant of the ISO standardised LOTOS language. It includes basic data types and a few enhancements compared with the LOTOS standard. The enhancements increase the usability of the language in verification by enabling compositional analysis of processes, providing new control mechanisms for state space generation and increasing the level of abstraction in the modelling. Some restrictions caused by the requirements of state space generation have also been introduced to the language. The formal operational semantics of the input language are formulated mathematically by a collection of transition rules. We also give for some constructs of the language reduction rules that preserve strong observation equivalence. We describe the implementation of the tool at a general level, with a few special methods and algorithms used in the implementation presented in more detail.