;; Graphs with both Directed and Undirected Edges

(define bg (bingraph))		

(add-vertices! 1 3 bg)

(define vseq (sequence-vertex (vertex-ref bg 2) (vertex-ref bg 0)))
(define vset (set-vertex      (vertex-ref bg 2) (vertex-ref bg 0)))

(add-edge! vseq bg)
(add-edge! vset bg)

(describe bg)
