Furthermore , with the induction of precision order of a type - function u ( r ) , the necessary and sufficient conditions of the dirichlet series , which keep unaltered the order and the type , are obtained . such a result naturally has a bearing on " rearrangement problem " of power series and abel summable series 此外，当狄里克莱级数引入精确级后，得到了有限级狄里克莱经过重排后的精确级以及关于型函数u ( r )的型保持不变的充要条件。
