Hi,

I am not sure about the notation of a case by case problem. This is my solution:

$\displaystyle E[I]=\begin{cases} <0 & \text{for}\quad l>0 \quad \text{and} \quad \mu<i\left(1-\frac{1}{l}\right)+\frac{l\sigma^2}{2}\\ <0 & \text{for}\quad l<0 \quad \text{and} \quad \mu>i\left(1-\frac{1}{l}\right)+\frac{l\sigma^2}{2}\\\geq0 & otherwise\end{cases}$

Is that the correct way to display a case by case analysis? Specifically I would like to know, if there is a more elegant way than my solution. Is the phrasing "for" and "and" the way to do it? What about "otherwise"? I have only little experience in mathematical notation and therefore I'd be glad about comments about my "mathematical style"

Thanks