support xr-hyper (xr) in auctex and reftex

[Uwe Brauer]

Hi

Only by now I realised that xr-hyper allows me to set a (hyperref)
reference to an external document.

Here is a minimal example 
master
,----
| \documentclass[12pt]{article}
| \usepackage{amsmath,amsthm}
| \usepackage{xr-hyper}
| \usepackage[colorlinks]{hyperref}
| 
| \begin{document}
| this is an equation 
| \begin{equation}
| \label{eq:master1}
|   \int f dx
| \end{equation}
| \end{document}
`----
,----
| \documentclass[12pt]{article}
| \usepackage{xr-hyper}
| \usepackage[colorlinks]{hyperref}
| \externaldocument{master}
| \begin{document}
| 
| This is true
| \ref{eq:master1}
| 
| \end{document}
| 
`----

To have a separate style for xr or xr-hyper seems a bit pathetic since
it only would need

  (TeX-add-symbols
   '("externaldocument" [ "Option" ] "LaTeX Dokument" "PDF-document"))

However, it would be very helpful to have reftex support that. 
Right now reftex supports input, include and subfiles but not xr-hyper.

Anybody interested in this?

Regards

Uwe Brauer