Each pair of these edges forms a two-edge loop. This is in the right part in Figure 3 . This is in the left part in Figure 3 . We will follow all of the x m and x m vertices from top to bottom. And then, we traversed the B widgets from bottom to top.
G contains a Hamiltonian-cycle.
G s left side from top to bottom. Because the value of x m is 1, we traverse e m . So we can visit all vertices in each copy of B widget. G forming a cycle. Is there is a subset S S whose elements sum to t.