Algebraic Specification of Systems of Concurrent Components

Grant Malcom

(Liverpool University)

We examine the use of algebraic theories in specifying evolving systems,
by which we mean systems of objects where objects may be created and
destroyed, and where relationships between objects may change.
In particular, we look at how such systems can be modelled by
evolving specifications: rather than having one specification
describing a system, a hierarchically structured specification
describes a state of the system; as the state of the system changes,
so too does the hierarchically structured specification.

Our main concern is in developing the model theory
of such evolving systems, building on top
of hidden algebra. Hidden algebra was introduced by Goguen as a formal
basis for semantics of systems of interacting objects, and allows the
specification of concurrent, interacting objects through the so-called
concurrent connection. This is an operation that works at the level of
specifications; i.e., two specifications, each specifying an object, and
possibly interacting through a shared subcomponent, can be combined to
give a specification of a system comprising the two objects, together
with any shared subcomponents. Our evolving specifications can be
viewed as a system of concurrent connections of hidden algebraic
theories.

Tuesday 3rd March 2009, 14:00
Robert Recorde Room
Department of Computer Science