Index: index.html
===================================================================
--- index.html	(revision 9679)
+++ index.html	(revision 9680)
@@ -13,7 +13,7 @@
 <ul class="toc">
 	<li><a href="01_intro/index.html">   1. Introduction </a>
 	<li><a href="02_model/index.html">   2. Model of the world </a>
-	<li><a href="03_data/">    3. Where data is stored </a>
+	<li><a href="03_data/index.html">    3. Where data is stored </a>
 	<li><a href="04_invoc/index.html">      4. Program Invocation </a>
 	<li><a href="05_ui/index.html">   5. Graphical and Batch User Interfaces </a>
 	<li><a href="06_feature/"> 6. Feature plugins </a>