The Effects of Timing Dependence and Recursion on Parallel Program Schemata

We are interested in the effects of timing dependence and recursion in the class of parallel program schemata. We compare the expression power of some classes of dataflow schemata: UDF, DF_π, RDF etc. DF_π includes a π-gate which introduces timing dependence, and RDF has a facility for recursion and UDF has both devices. In conclusion, we show some inclusion relations between classes, including the existence of a class standing between EF and EFd. These relations reveal the role of timing dependence and recursion.