Index: openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl,v
diff -u -N -r1.41.2.2 -r1.41.2.3
--- openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl	21 Aug 2019 06:47:07 -0000	1.41.2.2
+++ openacs-4/packages/tsearch2-driver/tcl/tsearch2-driver-procs.tcl	4 Feb 2020 08:52:53 -0000	1.41.2.3
@@ -275,9 +275,12 @@
     # remove "not" at end of query
     regsub -nocase " not$" $query {} query
 
+    # remove "not" alone
+    regsub -nocase "^not$" $query {} query
+
     # replace boolean words with boolean operators
     regsub -nocase "^not " $query {!} query
-    set query [string map {" and " " & " " or " " | " " not " " ! "} " $query "]
+    set query [string map {" and " " & " " or " " | " " not " " ! "} $query]
 
     # remove leading and trailing spaces so they aren't turned into &
     set query [string trim $query]