lamy@cs.toronto.edu (Jean-Francois Lamy) (11/23/89)
It turns out that AT&T has a tool in their latest research Unix that appears to do a good job for DAGs, and handles cyclic directed graphs in a reasonable way as well. We're negociating for access to that program. Alberto mentions that he has a fair number of references on the topic, and several people have sent me lists of such. Thanks to all who responded.