ALE source-level debugger installation instructions
***The debugger requires SICStus Prolog 3.0.6 or higher***
 1. Make the debugger directory in the ALE distribution the current directory
 2. Edit the file Makefile.
      A. set XEMACS to the command that runs XEmacs (version 19.15 or higher),
         if you want to use the debugger with XEmacs
      B. set SICSTUS to the command that runs SICStus Prolog (version 3.0.6
         or higher)
 3. To use the debugger with XEmacs, type:
      make emacs
    at your unix prompt. Ignore warnings.  If this does not create a file,
    sicstus-debug.elc, then your version of XEmacs is not recent enough.
    You can still use the ALE source-level debugger with the noemacs/0 
    option.

    To use the debugger only without XEmacs, type:
      make noemacs
    at your unix prompt.  You may stop at this step; but read the notes below.

 5. (XEmacs only) Run XEmacs, load dot.emacs and follow the 3 steps therein:
      A. paste all of the code in dot.emacs into your .emacs file.
         If you insert it after code that contains an error, XEmacs may not
         use it!
      B. put the directory where the SICStus 3.0.6 version of prolog.el can
         be found between the pair of double-quotes on the indicated line.
         This is usually the root directory of the SICStus distribution.
         The ALE source-level debugger will not work with earlier versions of 
         prolog.el.
      C. put the full path of sicstus-debug.elc from step 3,
         including the filename itself, between the pair of 
         double-quotes on the indicated line.

end of installation instructions

Notes:
   - You will need to restart XEmacs before using the debugger.
   - To use the debugger with XEmacs, you must run SICStus Prolog inside
     XEmacs as an inferior process.  The XEmacs command for this is 
     M-x run-prolog.  This will try to run SICStus Prolog with the command,
     sicstus.  If the command to run SICStus Prolog is something else, you
     must set the environment variable, EPROLOG, to that command in the shell
     that runs XEmacs.
