Getting things to work.

First you need to have XEmacs 21.1 or later installed. Then you need to get and install Proof-General version 3.3 or later. Remember where you installed Proof-General.

Then you need to add the following line to the configuration file of XEmacs^2.1:

(load-file
  "/usr/share/emacs/site-lisp/ProofGeneral/generic/proof-site.el")

This line is valid if Proof-General is installed in /usr/share/emacs/site-lisp. Adapt it to your own setup. If later fails to start, you can also add a line

(set-variable 'phox-prog-name
  "/usr/local/bin/phox -pg")

The -pg is essential when works with Proof-General.