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\begin{verbatim}
#include<iostream.h>
#include<LINK/graph/DBinGraph.h>
#include<LINK/basic/Set.h>
#include<LINK/basic/Sequence.h>

main()
{
        DBinGraph g1;

        g1.addVertices(4);
        Vertex** vertices = g1.vertexStart();
        int num_vertices = g1.order();

        for (int i=1; i<num_vertices; i++) {
                Sequence<Vertex*> s;
                s.append(vertices[i]);
                s.append(vertices[i-1]);
                g1.addEdge(s);
        }
        cout << g1 << endl;
}
\end{verbatim}

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\begin{verbatim} 
{[0 1 2 3]  {<1 0> <2 1> <3 2>}}
\end{verbatim}

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