Specifying component and context specification using Promotion

In this paper we discuss how the specification of components may be separated from the description of the context in which they are used. There are a number of ways in which this might be possible and here we show how to use the technique of promotion in Object-Z to combine components which are specified using process algebras. We discuss two approaches, the first is to separate out the specification into two distinct viewpoints written in different languages. These viewpoints are then combined by a process of translation and unification. The second approach will be to use hybrid languages composed of a combination of CSP and Object-Z. We also consider how to refine such component based descriptions and consider issues of compositionality.