Abstraction and Testing in CSP

Restricted views of process behaviour result in a form of abstraction which is useful in the construction of specifications involving fault-tolerance and atomicity. This paper presents an operational characterisation of abstraction for refusable and non-refusable events in terms of testing. This view is a generalisation of standard notions of testing, and is given a new denotational characterisation encapsulated within the CSP denotational semantics. It informs, reinforces and extends the traditional denotational approach to abstraction. Received February 2000 / Accepted in revised form April 2000