Composition of Model Programs

Model programs are a useful formalism for software testing and design analysis. They are used in industrial tools, such as SpecExplorer, as a compact, expressive and precise way to specify complex behavior. One of the challenges with model programs has been the difficulty to separate contract modeling from scenario modeling. It has not been clear how to separate those concerns in a clean way. In this paper we introduce composition of model programs, motivate why it is useful to be able to compose model programs, and what composition of model programs formally means.