Whenever I'm out of ideas I always end up going back to the Propagator/Logic Simulator chapters of SICP and rewriting them hoping to glean a bit more about the process and usability of such an abstraction. I usually end up writing a Propagating logic simulator (combining the chapters) and marveling at the working forward/backward ripple carry adder. This time I've derived all the way down to switches which infer unkn…
Now, to go back and the propagator network and read the Scheme-Propagators source.