A formal approach to open multiparty interactions

Abstract

We present a process algebra aimed at describing interactions that are multiparty, i.e. that may involve more than two processes and that are open, i.e. the number of the processes they involve is not fixed or known a priori. Here we focus on the theory of a core version of a process calculus, without message passing, called Core Network Algebra (CNA). In CNA communication actions are given not in terms of channels but in terms of chains of links that record the source and the target ends of each hop of interactions. The operational semantics of our calculus mildly extends the one of CCS. The abstract semantics is given in the style of bisimulation but requires some ingenuity. Remarkably, the abstract semantics is a congruence for all operators of CNA and also with respect to substitutions, which is not the case for strong bisimilarity in CCS. As a motivating and running example, we illustrate the model of a simple software defined network infrastructure.

SOS Rules for Equivalences of Reaction Systems

“…In Brodo et al [9,10] we derived similar results to those presented here by encoding RSs into cCNA, a multi-party process algebra (a variant of the linkcalculus [5,6]). In comparison with the encoding of RS in cCNA, we get here a much simpler computational model, closer to the syntax of RSs, preserving the expressiveness at the level of transition labels.…”

Enhancing Reaction Systems: A Process Algebraic Approach

“…The operational semantics of cCNA is defined in the SOS style by the inference rules in Fig.1. The rules are reminiscent of those for Milner's CCS and they essentially coincide with those of CNA in [6]. The only difference is due to the presence of prefixes that are link chains.…”

“…In this paper we have introduced a variant of the link-calculus where prefixes are link chains and no more single links, as it was briefly described in the future work section in [6]. This variant allowed us to define an elegant embedding of reaction systems, an emerging formalism to model computationally biochemical systems.…”

“…We let 0, the inactive process, denote the empty summation. The syntax of cCNA extends that of CNA [6] by allowing to use link chains as prefixes instead of links. For the rest it features nondeterministic choice, parallel composition, restriction, relabelling and possibly recursive definitions.…”

“…In this paper, we present an encoding from RSs, to the open multiparty process algebra cCNA, 4 a variant of the link-calculus [5,6] without name mobility.…”