(contains-directed-edge-p nil ar
"Returns true if graph contains at least one directed edge. [?? Not sure if this is really keep up-to-date.]")
(contains-undirected-edge-p nil ar
(contains-directed-edge-p nil ar
"Returns true if graph contains at least one directed edge. [?? Not sure if this is really keep up-to-date.]")
(contains-undirected-edge-p nil ar