I am writing a big formula where a vertical line is needed. Instead of $\vline$ or $|$, does anyone know a way to draw this vertical line of desired length? The formula is something like
$$
E\Bigg[
F_{m-1}\Big( \text{some big contents} \Big) |\: \mathcal{F}_1
\Bigg]
$$
Thank you very much!

mathmodedocumentation is very helpful. It should be part of your TeX distribution. – Alan Munn Jan 02 '11 at 18:53