dges (or arcs) that connect the vertices. <a href="#fig:quick-start">Figure 2</a>
depicts a directed graph with five vertices (labeled 0 through 4) and 11 edges.
The edges leaving a vertex are called the <i>out-edges</i> of the vertex. The
edges <tt>{(0,1),(0,2),(0,3),(0,4)}</tt> are all out-edges of vertex 0. The
edges entering a vertex are called the <i>in-edges</i> of the vertex. The edges <tt>{(0,4),(2,4),(3,4)}</tt>
are all in-edges of vertex 4.
<p>&nbsp;</p>
<div align="CENTER">
  <a name="fig:quick-s