Published online by Cambridge University Press: 05 August 2012
From ATM machines dispensing cash from our bank accounts, to online shopping websites, interactive systems permeate our everyday life. The underlying technology to support these systems, both hardware and software, is well advanced. However design principles and techniques for assuring their correct behaviour are at a much more primitive stage.
The provision of solid foundations for such activities, mathematical models of system behaviour and associated reasoning tools, has been a central theme of theoretical computer science over the last two decades. One approach has been the design of formal calculi in which the fundamental concepts underlying interactive systems can be described, and studied. The most obvious analogy is the use of the λ-calculus as a simple model for the study of sequential computation, or indeed the study of sequential programming languages. CCS (a Calculus for Communicating Systems) [28] was perhaps the first calculus proposed for the study of interactive systems, and was followed by numerous variations. This calculus consists of:
A simple formal language for describing systems in terms of their structure; how they are constructed from individual, but interconnected, components.
A semantic theory that seeks to understand the behaviour of systems described in the language, in terms of their ability to interact with users.
Here a system consists of a finite number of independent processes that intercommunicate using a fixed set of named communication channels. This set of channels constitutes a connection topology through which all communication takes place; it includes both communication between system components, and between the system and its users.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.