Executable Tile Speciications for Process Calculi ?

Tile logic extends rewriting logic by taking into account side-eeects 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 eeorts, an executable speciication of tile systems can be obtained by mapping tile logic back into rewriting logic, in a conservative way. However, a correct rewriting implementation of tile logic requires the development of a metalayer to control rewritings, i.e., to discard computations that do not correspond to any deduction in tile logic. We show how such methodology can be applied to term tile systems that cover and extend a wide-class of SOS formats for the speciication of process cal-culi. The well-known 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, as a signiicative example.