Management of Evolving Specifications using Category Theory

Structure is important in large speci cations for understanding, testing and managing change. Category theory has been explored as framework for providing this structure, and has been successfully used to compose speci cations. This work has typically adopted a \correct by construction" approach: components are speci ed, proved correct and then composed together in such a way to preserve their properties. However, in a large project, it is desirable to be able to mix speci cation and composition steps such that at any particular moment in the process, we may have established only some of the properties of the components, and some of the composition relations. In this paper we propose adaptations to the categorical framework in order to manage evolving speci cations. We demonstrate the utility of the framework on the analysis of a part of a software change request for the Space Shuttle.