A page about the pi calculus (and Business Process Management)
Contact mailto:howard.smith@ontology.org
This page was set up to collect materials that I personally found useful in understanding the pi calculus. It goes without saying that the pi calculus and its predecessor, CCS, a general theory of concurrency, are very significant contributions to computer science. This page will be expanded over time.
Turing, Computing and Communication
Robin
Milner, King's College, October 1997
[PDF]
A
lecture by the founding father of the pi calculus, though he would immediately
urge me to say that pi calculus, and concurrency theory in general, is a huge
field to which many individuals have each made significant contributions.
In particular, he would expect me to mention his colleagues Joachim Parrow, David Walker and Davide Sangiorgi. See also a page about Robin Milner.
Computing in Space
Robin Milner, Cambridge University,
May 2002
[PDF]
A lecture by Robin Milner, for the opening of the Computer Laboratory's William Gates Building at the University of Cambridge, on 1 May 2002. Here, Robin expands upon the pi calculus and introduces the notions of ambients and bigraphs, in which the nesting of nodes represents locality, independently of the edges connecting them.
The pi calculus, an Audio and Visual Tutorial
anon
[Real Audio and PDF]
From one of the largest repositories of Computer Science courseware, developed through a U.S. National Science Foundation Education Infrastructure Project in the Department of Computer Science at Virginia Tech. Includes an audio lecture and corresponding slide set, being an excellent introduction to the pi calculus.
Workflow is just a Pi process
A paper which examines the
inability of today's workflow engines to support advanced workflow patterns,
how Pi calculus based technologies are able to do this, and model many other
processes not addressed by workflow systems. Howard Smith and Peter Fingar,
October 2003
[PDF]
The Theoretical Foundations of the Third Wave
Howard Smith and Peter
Fingar, December 2002
[PDF]
Appendix C to Business
Process Management: The Third Wave. ISBN 0929652339. www.bpm3.com.
Here, Peter Fingar and I provide, for the general “business-technology” reader,
a flavor of why we feel pi calculus is critical to the expression and management
of business processes.
Communicating and mobile systems: the pi calculus
Robin Milner, ISBN
052164320, Cambridge University Press
[BOOK]
The seminal book on pi calculus.
From the Preface: “Communication is a fundamental and integral part of computing,
whether between different computers on a network, or between components within
a single computer. In this book Robin Milner introduces a new way of modeling
communication which reflects his position. He treats computers and their programs
as themselves built from communicating parts, rather than adding communication
as an extra level of activity … The pi calculus differs from other models
of communicating behavior mainly in its treatment of mobility. The movement
of a piece of data inside a computer science is treated exactly the same as
the same transfer of a message—or indeed an entire computer program—across
the Internet. One can also describe networks which reconfigure themselves.
The calculus is very simple but powerful. Its most prominent notion is that
of a name, and it has two importants ingredients: the concept of behavioral
(or observational equivalence), and the use of a new theory of types to classify
patterns of interactive behavior. The Internet, and its communication protocols,
fall within the scope of the theory, just as much as computer programs, data
structures, algorithms and programming languages [HS: and languages for modeling
business processes].”
Lucian Wischik, University
of Bologna, August 2002
[PDF]
A paper, primarily motivated
to introduce a new distributed implementation of the pi calculus,
Silvano Dal Zilio, Microsoft
Research
[PDF]
A short bibliographic survey
of calculi for mobile processes. Considers both labile processes, which can
exhibit dynamic changes in their interaction structure, as modelled by the
pi calculus of Milner, Parrow and Walker for example, and motile processes,
which can exhibit motion, as modelled in the ambient calculus of Cardelli
and Gordon. For those wanting to read around the subject of process calculus,
this paper presents a check list of some of the most important work focussing
on different aspects of the topic.
The pi calculus: A Theory of Mobile Processes
Davide Sangiorgi & David
Walker, ISBN 0521781779
[BOOK]
A book only for pure mathematicians
and advanced computer scientists working in the field of concurrency theory
and formal proofs. This book can be said to represent the very latest published
theoretical work in the field (at least in the form of a book!).