generalization of star-mesh transformation

it is well know that any three impedances or admittances connected into each other in a star form can be easily transformed to a new three impedances or admittances connected into each other in a mesh form. in this paper a generalization of this fact is established and it is shown that in an n + 1 node network which is connected in a form it is always possible to eliminate the center node and obtain a new n-node network with a complete graph and the new values of branch impedances or admittances, without effecting any of the node voltages or branch currents relationship. this generelization has useful applications in simplifying complicated networks.