> If an org file contains a latex equation with a '&' in it then when it is
> exported to odt it makes dodgy xml.  Unzipping the odt, opening the
> content.xml and doing M-x rng-first-error gives the message:
>
> `&' that is not markup must be entered as `&'
>
> To reproduce, insert this:
>
> \begin{equation}
> \delta_{mn} = 
>  \begin{cases}
>   1& \text{if $n=m$}\\
>   0& \text{if $n\nem$}
>  \end{cases}
> \end{equation}
>
> (which I got from here
> http://www.mathtoweb.com/cgi-bin/mathtoweb_users_guide.pl , search for
> 'cases')
>
> into the file math-to-web-with-plastex.org in this post:
> http://permalink.gmane.org/gmane.emacs.orgmode/48815 and export as per
> instructions.
>
> There may be a similar error with equations containing '<', '>'.