You might find this paper interesting: http://www.iro.umontreal.ca/~feeley/papers/BergeronFeeleyDavidNEWCAS07.pdf http://www.iro.umontreal.ca/~feeley/papers/Ber

You might find this paper interesting: http://www.iro.umontreal.ca/~feeley/papers/BergeronFeeleyDavidNEWCAS07.pdf http://www.iro.umontreal.ca/~feeley/papers/BergeronFeeleyDav... Edit: found PDF link.