Non-interleaving Operational Semantics for the Pi-calculus – technicalities

We provide a non-interleaving operational semantics for the pi-calculus as asynchronous transition systems, which generalizes the standard interleaving structural operational semantics and unfolds to standard, stable prime event structures. We follow the approach taken by Mukund and Nielsen in providing non-interleaving semantics for CCS by infering the so-called prefixing (structural or subjective) causality between actions from a notion of locations derived from the syntactic structure of the term. We then introduce a notion of extruder histories, from which we infer the so-called name (link or objective) causality that the dynamic communication topology of the pi-calculus introduces. The notion of extruder histories is inspired by recent work of Crafa, Varacca, and Yoshida providing an elegant non-interleaving denotational semantics for pi-calculus, but in a model of non-stable extended event structures. Address: IT University of Copenhagen, Rued Langgaardsvej 7, 2300 Copenhagen, Denmark. Email: [email protected] Department of Informatics, University of Oslo, P.O. Box 1080 Blindern, 0316 Oslo, Norway. Email: [email protected] (neé Cristian Prisacariu) Address: IT University of Copenhagen, Rued Langgaardsvej 7, 2300 Copenhagen, Denmark. Email: [email protected]