Stuttering Congruence for χ

The language χ is a modeling and simulation language which is currently mainly used to analyse and optimize the performance of industrial systems. To be able to also verify functional properties of a system using a χ model, part of the language has been given a formal semantics. Rather than implementing a new model checker for χ, the philosophy is to provide automatic translations from χ into the specification languages of existing state-of-the-art model checkers such as, e.g., spin and uppaal. In this paper, we propose for χ a notion of stuttering congruence, which is an adaptation of the notion of stuttering equivalence. We prove that our notion preserves the validity of ctl−x formulas, that it preserves deadlock, and that it is indeed a congruence with respect to the constructs of χ. We also indicate how our notion is to be used to establish confidence in the correctness of a translation from χ into promela.