# Single quotes in mathtext

Jos?> Hello, I think I've found a bug in mathtext - sorry if this
Jos?> appeared before, I couldn't find it in the list archives.

Jos?> When I try:

Jos?> xlabel(r"$-(\Omega_a^' + \Omega_a)$")

Jos?> I don't get what I expected. The label shows -\Omega_a and
Jos?> stops there. Further tests showed that, whenever I try a
Jos?> single quote in a mathtext string, the text is not rendered
Jos?> from the quote on.

Jos?> This might not be a bug, I might be doing something
Jos?> wrong. If this is the case, please tell me how to do it
Jos?> right.

I don't believe your use of ' is valid TeX. Try
Omega_a^\prime