Modular Completeness: Integrating the Reuse of Specified Software in Top-down Program Development

Reuse of correctly specified software is crucial in bottomup program development. Compositional specification formalisms have been designed to reduce the specification of a syntactically composed construct to specifications of its components, and therefore support topdown development methodology. Thus, the integration of reuse of correctly specified software components in a compositional setting calls for adaptation of a given specification to specifications needed in particular circumstances (depending on their application). Proof systems in which such adaptation steps can be performed whenever they are valid are called modular complete [Z89]. We present a generic way of constructing such systems for sequential and concurrent Hoare logics.