+ * Revision 1.9 1996-10-29 13:55:21 adam
+ * Include of zebrautl.h instead of alexutil.h.
+ *
+ * Revision 1.8 1995/12/11 09:15:23 adam
+ * New set types: sand/sor/snot - ranked versions of and/or/not in
+ * ranked/semi-ranked result sets.
+ * Note: the snot not finished yet.
+ * New rset member: flag.
+ * Bug fix: r_delete in rsrel.c did free bad memory block.
+ *
+ * Revision 1.7 1995/10/12 12:41:56 adam
+ * Private info (buf) moved from struct rset_control to struct rset.
+ * Bug fixes in relevance.
+ *
+ * Revision 1.6 1995/09/08 14:52:41 adam
+ * Work on relevance feedback.
+ *
+ * Revision 1.5 1995/09/07 13:58:43 adam
+ * New parameter: result-set file descriptor (RSFD) to support multiple
+ * positions within the same result-set.
+ * Boolean operators: and, or, not implemented.
+ *
+ * Revision 1.4 1995/09/06 16:11:56 adam
+ * More work on boolean sets.
+ *
+ * Revision 1.3 1995/09/04 15:20:39 adam
+ * More work on temp sets. is_open member removed.
+ *
+ * Revision 1.2 1995/09/04 12:33:56 adam
+ * Various cleanup. YAZ util used instead.
+ *
+ * Revision 1.1 1994/11/04 13:21:28 quinn