To get many of the prolog features to work with emacs, you will need to copy this into your .emacs file. You will probably want to make a backup copy of your .emacs before attempting this.

;;;Prolog
 (setq load-path
 (cons (expand-file-name "/util/sicstus-3.9.1/lib/sicstus-3.9.1/emacs")
        load-path))
 (autoload 'run-prolog "prolog" "Start a Prolog sub-process."  t)
 (autoload 'prolog-mode "prolog" "Major mode for editing Prolog  programs." t)
 (setq prolog-use-sicstus-sd t)
 (setq auto-mode-alist (cons '("\\.prolog$" . prolog-mode) auto-mode-alist)) 
 (setq Info-default-directory-list (append Info-default-directory-list 
 '("/util/sicstus-3.9.1/lib/sicstus-3.9.1/doc/info")))