Compositional event structure semantics for the internal pi-calculus

We propose the first compositional event structure semantics for a very expressive pi-calculus, generalising Winskel’s event structures for CCS. The pi-calculus we model is the piI-calculus with recursive definitions and summations. First we model the synchronous calculus, introducing a notion of dynamic renaming to the standard operators on event structures. Then we model the asynchronous calculus, for which a new additional operator, called rooting, is necessary for representing causality due to new name binding. The semantics are shown to be operationally adequate and sound with respect to bisimulation.