The following is the copyright notice for the indexing concept and
algorithms used in colab/RFM/index:

;;; Copyright Notice
;;;
;;; This software is distributed for non-profit and research purposes only.
;;; I retain the exclusive right of producing a commercial version from it.
;;; Non-profit redistribution of the current version or parts of the
;;; current version is permitted if this copyright notice is included
;;; unchanged.  I give no warranty of any kind for this prototype. It will be
;;; further improved as time permits.
;;; 
;;; Copyright (c) 1991/1992 by Michael Sintek and Werner Stein

