A composite demo with a Giotto model embedded in a DE model.
The Giotto model is driven by two seperate events according
to the DE semantics.
The model consists of a constant source that produces the value 1, a pair of composites that function as accumulators, simply adding the current value to a running sum, and a plotter. The source and the upper composite run at frequency 1, meaning that they get invoked once per iteration. The lower composite and the plotter run at frequency 2, meaning that they are invoked twice per iteration.
The composites are defined as follows: