[OS X TeX] colorbox

[Alan Munn]

At 10:28 PM -0400 7/27/08, Alain Schremmer wrote:
>This is just a LaTeX question but I have already 
>wasted a couple of hours on it. So, I hope, Š
>
>I would like to have the same highlighting effect as in
>
>	$f(x)$\colorbox{yellow}{$\left.\right|_{x:=-3}$}
>
>but of course, since the delimiters do not take 
>the height of the front into account, with
>
>	$\dfrac{x}{x-1}$\colorbox{yellow}{$\left.\right|_{x:=-3}$}
>
>  the vertical bar is too short and I am not able 
>to move \left. to the left of the fraction.

How about:

\newlength{\foo}
\settoheight{\foo}{$\dfrac{x}{x-1}$}

$\dfrac{x}{x-1}$\colorbox{yellow}{$\left.\rule{0pt}{\foo}\right|_{x:=-3}$}

Alan