Syllogism demo

Initial pull request for testing syllogisms. Work in progress. Not to be merged yet. Comments welcome.
They both seem useful; i.e. it is useful to break the pipeline into parts for isolated testing purposes; but it is very nice to provide a complete demonstration end-to-end of the pipeline as well.

I suggest that for now, as a preliminary step, whatever is feasible in the remaining timeframe is the preferred path.