anchor.diff:          result)))
   
   (defun prompt-for-library (prompt history-name)
  -  (let ((systems (append
  -                  (mapcar (lambda (x) (pathname-name x))
  -                          (directory
  -                           (merge-pathnames "**/lem-*.asd"
  -                                            (asdf:system-source-directory :lem-contrib))))
  -                  (set-difference
  -                   (mapcar #'pathname-name
  -                           (loop for i in ql:*local-project-directories*
  -                                 append (directory (merge-pathnames "**/lem-*.asd" i))))
  -                   (mapcar #'pathname-name
  -                           (directory (merge-pathnames "**/lem-*.asd" (asdf:system-source-directory :lem))))
  -                   :test #'equal))))
  +  (let ((systems
  +          (append
  +           (mapcar (lambda (x) (pathname-name x))
  +                   (directory
  +                    (merge-pathnames "**/lem-*.asd"
  +                                     (asdf:system-source-directory :lem-contrib))))
  +           (set-difference
  +            (mapcar #'pathname-name
  +                    (loop for i in ql:*local-project-directories*
  +                          append (directory (merge-pathnames "**/lem-*.asd" i))))
  +            (mapcar #'pathname-name
  +                    (directory (merge-pathnames "**/lem-*.asd"
  +                                                (asdf:system-source-directory :lem))))
  +            :test #'equal))))
       (setq systems (mapcar (lambda (x) (subseq x 4)) systems))
       (prompt-for-line prompt ""
                        (lambda (str) (completion str systems))
  
positive.code:   (when (and (not *enable-recursive-minibuffers*) (< 0 *minibuf-read-line-depth*))
      (editor-error "ERROR: recursive use of minibuffer"))
    (let ((*minibuffer-calls-window* (current-window))
          (*minibuf-read-line-history* (let ((table (gethash history-name *minibuf-read-line-history-table*)))
                                         (or table
                                             (setf (gethash history-name *minibuf-read-line-history-table*)
                                                   (lem.history:make-history))))))
      (let ((result
              (catch +recursive-minibuffer-break-tag+
                (handler-case
  
negative.code:                                            (end (current-point)))
                                  (line-start start)
                                  (line-offset end 0 prev-prompt-length)
                                  (put-text-property start end
                                                     :attribute 'minibuffer-prompt-attribute)
                                  (put-text-property start end :read-only t)
                                  (put-text-property start end :field t)))
                              (move-point (current-point) minibuf-buffer-prev-point)
  