Micha Feigin writes:
>
> how do I generate a group definition such as
> { x | x > 0 }
> with variable height braces? I can create the outside braces using left\{
> and right\} (or matching braces from the braces menu) but the central one
> doesn't fit it, and if I add a | with a matching empty left or right
> element the sizes don't match
If you have a recent TeX engine, \middle| should do what you want.
LyX doesn't support it yet, so you will simply see \middle in red,
but it will work on output.
--
Enrico
