We have been developing a semantic model for Reo that allows us to calculate the behaviour of general Reo circuits. The resulting semantic model can also be used to capture the behaviour of circuits which express priority or other context sensitive behaviour.

The semantic model will be presented using an intuitive graphical representation in which calculating with the semantic rules resembles solving a jigsaw puzzle. During the talk the main decisions and solutions that were adopted will be outlined. We will unveil which problems our model can address and those which require further work.

A secondary benifit of our work is that the model can be used as a basis for an efficient distributed implementation of Reo. If time permits, we shall discuss the issues involved.