The Benz Theorem and the Aleksandrov Problem in 2-Normed Space *

In this paper, we introduce Benz theorem that is established without the condition "Y is strictly convex and ". The n the main theorem holds mainly by changing the type of space in (1) and weakening the conditions of the theorem in 2-normed space and in n-normed space. And the theorem 2.1 in (1) can be used as the corollary of theorem 2.3 in this paper. dim 2 X 