英语语法分析

The principal square root function is defined using the nonpositive real axis as a branch cut.

主平方根函数是使用非正实轴作为分支切割定义的。

But the range of exponential values is still not clear although it seems that all exponents are nonpositive real Numbers.

尽管猜想这些指数“似乎”都是非正实数，但对指数范围的实情并不明确。

We concluded that the covariance matrix is nonpositive definite, there is either arbitrage opportunity or efficient subset.

当协方差矩阵非正定时，要么存在套利机会，要么存在有效子集（即有多余的证券存在）。