Graph Representation of Sessions and Pipelines for Structured Service Programming

Graph transformation techniques, and the Double-Pushout approach in particular, have been successfully applied in the modeling of concurrent systems. In this area, a research thread has addressed the definition of concurrent semantics for process calculi. In this paper, we show how graph transformation can cope with advanced features of service-oriented process calculi, such as several logical notions of scoping (like sessions and pipelines) together with the interplay between linking and containment. This is illustrated by encoding CaSPiS, a recently proposed process calculus with such sophisticated features. We show how to represent the congruence and reduction relations between CaSPiS processes by exploiting concurrent graph transformations over hierarchical graphs.