Executable Tile Specifications for Process Calculi

Tile logic extends rewriting logic by taking into account side-effects and rewriting synchronization. These aspects are very important when we model process calculi, because they allow us to express the dynamic interaction between processes and “the rest of the world”. Since rewriting logic is the semantic basis of several language implementation efforts, we can define an executable specification of tile systems by mapping tile logic back into rewriting logic. In particular, this implementation requires the development of a metalayer to control rewritings, i.e., to discard computations that do not correspond to any deduction in tile logic. Our methodology is applied to term tile systems that cover and extend a wide-class of SOS formats for the specification of process calculi. The case study of full CCS, where the term tile format is needed to deal with recursion (in the form of the replicator operator), is discussed in detail.