--- a/AATree.st	Fri Mar 27 10:40:50 2015 +0100
+++ b/AATree.st	Fri Apr 10 08:55:43 2015 +0200
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 2009 by eXept Software AG
               All Rights Reserved
@@ -11,6 +13,8 @@
 "
 "{ Package: 'stx:libbasic2' }"
 
+"{ NameSpace: Smalltalk }"
+
 BinaryTree subclass:#AATree
 	instanceVariableNames:''
 	classVariableNames:''
@@ -44,6 +48,12 @@
     in the treeNode; this results in 25% more storage overhead as compared to a Red/Black or plain Binary tree.
     For performance data, see performance.
 
+    Usage:
+        As seen in the performance charts, AA trees offer better average and worst case
+        performance, with a lower best case performance. 
+        Thus providing a more predictable performance (within a factor of 2, as opposed to
+        a much wider range for sortedCollections)
+
     [author:]
         Original algorithm by Arne Andersson
         ported from wikipedia to smalltalk code by Claus Gittinger
@@ -314,9 +324,10 @@
 !AATree class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic2/AATree.st,v 1.8 2012-08-06 06:00:37 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/AATree.st,v 1.9 2015-04-10 06:55:43 cg Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic2/AATree.st,v 1.8 2012-08-06 06:00:37 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/AATree.st,v 1.9 2015-04-10 06:55:43 cg Exp $'
 ! !
+