******** fig9.67 **********

	void
	find_art( vertex v )
	{
		vertex w;

/*1*/		visited[v] = TRUE;
/*2*/		low[v] = num[v] = counter++;	/* Rule 1 */

/*3*/		for each w adjacent to v
		{
/*4*/			if( !visited[w] )	/* forward edge */
			{
/*5*/				parent[w] = v;
/*6*/				find_art( w );
/*7*/				if( low[w] >= num[v] )
/*8*/					printf("%v is an articulation point\n", v );
/*9*/				low[v] = min( low[v], low[w] );	/* Rule 3 */
			}
			else
/*10*/			if( parent[v] != w )	/* back edge */
/*11*/				low[v] = min( low[v], num[w] );	/* Rule 2 */
		}
	}