2) we prove that each edge of g joins a vertex of 1 and a vertex v2 g If it has a edge joins two vertices yi and y2 of v2 g odd simple path 令(uF=u02u1,u2,…,U2nyY1y2), even path 令y2≠u(0≤2n There is u; so that y2=u; The path(u, u1, U2,..., U;-1 29j+1, ,U2n,,y2) from u to y2% s Simple path(u, u1,u2,.,U y2), simple circuit 2,u+1…,u2ny1,y %j is odd number ☆ i is even number❖ 2) we prove that each edge of G joins a vertex of V1 and a vertex V2 ❖ If it has a edge joins two vertices y1 and y2 of V2 ❖ odd simple path ❖ (u=u0 ,u1 ,u2 ,,u2n,y1 ,y2 ),even path ❖ y2ui (0i2n) ❖ There is uj so that y2=uj . The path (u,u1 ,u2 ,,uj-1 , y2 ,uj+1,,u2n,y1 ,y2 ) from u to y2 , ❖ Simple path (u,u1 ,u2 ,,uj-1 ,y2 ),simple circuit (y2 ,uj+1,,u2n,y1 ,y2 ) ❖ j is odd number ❖ j is even number