If anyone is interested here is a library of classes emplementing structural graphs. It is a work in progress. I would welcome comments and suggestions (and criticism).
It really needs some heavy duty testing. The little test program I have only touches the surface.
Be warned, class B_TREE uses a lot of contracts and can therefore be really slow with assertions turned on. I haven't had several days of free processor time so I have not given it a full check with all assertions on. If anyone has a fast computer I would love to know how it fares.
The files are at:
https://svn.origo.ethz.ch/egraphs/Trunkit depends on another group of classes:
https://svn.origo.ethz.ch/jj-support/TrunkHope this can help someone,
Jimmy J. Johnson