Using the Reenement Calculus for Dataaow Processes Using the Reenement Calculus for Dataaow Processes

The reenement calculus, based on predicate transformer semantics, is proving useful in the construction of sequential programs. It is argued that the reenement calculus provides a suitable development formalism for (possibly real-time) dataaow-like processes. Conventional precondition and postcondition speciications of sequential programs are generalised to assumption and eeect speciications of processes. Such speciications may be given predicate transformer semantics and then formally reened to implementations in much the same way as precondition and postcondition speciications of sequential programs. A minimal collection of dataaow-process operators and associated reenement laws is considered. Small examples of dataaow-process development are presented to demonstrate the utility of the approach. The compositionality of the approach is considered in detail.