FDR3 - A Modern Refinement Checker for CSP

Abstract. FDR3 is a complete rewrite of the CSP refinement checker FDR2, incorporating a significant number of enhancements. In this paper we describe the operation of FDR3 at a high level and then give a detailed description of several of its more important innovations. This includes the new multi-core refinement-checking algorithm that is able to achieve a near linear speed up as the number of cores increase. Further, we describe the new algorithm that FDR3 uses to construct its internal representation of CSP processes-this algorithm is more efficient than FDR2's, and is able to compile a large class of CSP processes to more efficient internal representations. We also present experimental results that compare FDR3 to related tools, which show it is unique (as far as we know) in being able to scale beyond the bounds of main memory