Case2的图例和证明： 01 W1 W2 2 u Wk Wk 要点：Since contains a vertex that is not adjacent to u and a vertex that is not adjacent to v,the size of each of the graphs G and G2,is less than m.Case2的图例和证明： 要点：Since W contains a vertex that is not adjacent to u and a vertex that is not adjacent to v, the size of each of the graphs G’u and G’v is less than m