We present the a-calculus, a calculus of communicating systems in which one can naturally express processes which have changing structure. Not only may the component agents of a system be arbitrarily linked, but a communication between neighbours may carry information which changes that linkage. The calculus is an extension of the process algebra CCS, following work by Engberg and Nielsen, who added mobility to CCS while preserving its algebraic properties. The rr-calculus gains simplicity by removing all distinction between variables and constants; communication links are identified by names, and computation is represented purely as the communication of names across links. After an illustrated description of how the n-calculus generalises conventional process algebras in treating mobility, several examples exploiting mobility are given in some detail. The important examples are the encoding into the n-calculus of higher-order functions (the I-calculus and combinatory algebra), the transmission of processes as values, and the representation of data structures as processes. The paper continues by presenting the algebraic theory of strong bisimilarity and strong equivalence, including a new notion of equivalence indexed by distinctions-i.e., assumptions of inequality among names. These theories are based upon a semantics in terms of a labeled transition system and a notion of strong bisimulation, both of which are expounded in detail in a companion paper. We also report briefly on work-in-progress based upon the corresponding notion of weak bisimulation, in which internal actions cannot be observed. 0 1992 Academic Press, Inc.

A calculus of mobile processes, II

An Introduction to MultiAgent Systems.

From the Publisher:
Since the introduction of Hoares' Communicating Sequential Processes notation, powerful new tools have transformed CSP into a practical way of describing industrial-sized problems. This book gives you the fundamental grasp of CSP concepts you'll need to take advantage of those tools.Part I provides a detailed foundation for working with CSP, using as little mathematics as possible. It introduces the ideas behind operational, denotational and algebraic models of CSP. Parts II and III go into greater detail about theory and practice. Topics include: parallel operators, hiding and renaming, piping and enslavement, buffers and communication, termination and sequencing, and semantic theory. Three detailed practical case studies are also presented.For anyone interested in modeling sequential processes.

/pdf/the-theory-and-practice-of-concurrency-1kzi2sg7cs.pdf

The Theory and Practice of Concurrency

Publisher Summary
This chapter focuses on rewrite systems, which are directed equations used to compute by repeatedly replacing sub-terms of a given formula with equal terms until the simplest form possible is obtained. As a formalism, rewrite systems have the full power of Turing machines and may be thought of as nondeterministic Markov algorithms over terms rather than strings. The theory of rewriting is in essence a theory of normal forms. To some extent, it is an outgrowth of the study of A. Church's Lambda Calculus and H. B. Curry's Combinatory Logic. The chapter discusses the syntax and semantics of equations from the algebraic, logical, and operational points of view. To use a rewrite system as a decision procedure, it must be convergent. The chapter describes this fundamental concept as an abstract property of binary relations. To use a rewrite system for computation or as a decision procedure for validity of identities, the termination property is crucial. The chapter presents the basic methods for proving termination. The chapter discusses the question of satisfiability of equations and the convergence property applied to rewriting.

CHAPTER 6 – Rewrite Systems

We survey the literature available on the topic of domain-specific languages as used for the construction and maintenance of software systems. We list a selection of 75 key publications in the area, and provide a summary for each of the papers. Moreover, we discuss terminology, risks and benefits, example domain-specific languages, design methodologies, and implementation techniques.

https://people.cis.ksu.edu/~schmidt/505f14/Lectures/DSLbib.pdf

Domain-specific languages: an annotated bibliography

Systems can be described at various levels of abstraction: automata, processes and behavior. In this paper, we take the ready trace set as a description of the behavior of a process and we present a ready trace model of real time process algebra. We argue that, especially in the real time case, properties of ready trace sets are best formulated in a dedicated logic (as opposed to describing them in an enriched process notation, such as ACPτ). We present the syntax and semantics of a logic that could serve this purpose and we apply it to study the existence of socalled coordinated attack protocols. A connection is made with the metric temporal logic of Koymans. This paper is an abbreviated version of [BABB93].

A real-time process logic

We propose a process algebra obtained by extending a combination
of the process algebra with continuous relative timing from Baeten
and Middelburg [Process Algebra with Timing, Springer, Chap. 4, 2002]
and the process algebra with propositional signals from Baeten and
Bergstra [Theoretical Computer Science 177:381–405, 1997]. The proposed
process algebra makes it possible to deal with the behaviour of
hybrid systems, i.e. systems in which the instantaneous state transitions
caused by performing actions are alternated with continuous state evolutions.
This process algebra has, in addition to equational axioms, rules
to derive equations with the help of real analysis.

Process algebra for hybrid systems

Presents a brief introduction to a process theory suitable for the specification of parallel or distributed systems of computers and for the description of the semantics of a parallel programming language. Algebraic notation is used to explain parallel intercommunicating processes involving computers

Processen en procesexpressies

Each Boolean function can be computed by a single-pass instruction sequence that contains only instructions to set and get the content of Boolean registers, forward jump instructions, and a termination instruction. Auxiliary Boolean registers are not necessary for this. In the current paper, we show that, in the case of the parity functions, shorter instruction sequences are possible with the use of an auxiliary Boolean register in the presence of instructions to complement the content of auxiliary Boolean registers. This result supports, in a setting where programs are instruction sequences acting on Boolean registers, a basic intuition behind the storage of auxiliary data, namely the intuition that this makes possible a reduction of the size of a program.

Instruction sequence size complexity of parity

/pdf/an-operational-semantics-for-process-algebra-43pu4300gf.pdf

Jan A. Bergstra

Papers

A real-time process logic

Process algebra for hybrid systems

Processen en procesexpressies

Instruction sequence size complexity of parity

An operational semantics for process algebra