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


main()
{
        MDBinGraph mg;
        DBinGraph g;
        Sequence<Vertex*> s;
        Vertex *v1, *v2;

        v1 = mg.addVertex("v1");
        v2 = mg.addVertex("v2");
        s.append(v1); s.append(v2);
        mg.addEdge(s); mg.addEdge(s);
        cout << mg << endl;
        
        s.clear();

        v1 = g.addVertex("v1");
        v2 = g.addVertex("v2");
        s.append(v1); s.append(v2);
        g.addEdge(s); g.addEdge(s);
        cout << g << endl;
}
\end{verbatim}

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\begin{verbatim} 
{[v1 v2]  {<v1 v2> <v1 v2>}}
{[v1 v2]  {<v1 v2>}}
\end{verbatim}

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