一個ｎ維緊緻超曲面最小浸入一個(n+1)維局部對稱空間，吾人給予條件
使此浸入之第二基本式的長度平方為常數．

Let M be an n-dimensional compact hypersurface which is
minimally immersed in an (n+1)-dimensional locally symmetric
space N. We give conditions such that the square of the length
of the second fundamental form of this immersion is constant.