CONTRIBUTORS

--- a/CONTRIBUTORS	Sat Nov 04 13:19:04 2006 +0100
+++ b/CONTRIBUTORS	Sat Nov 04 19:25:34 2006 +0100
@@ -2,6 +2,9 @@
 Contributions to Isabelle
 -------------------------
 
+* October 2006: Stefan Hohe, TUM
+  HOL-Algebra: ideals and quotients over rings.
+
 * August 2006: Amine Chaieb, TUM
   Experimental support for generic reflection and reification in HOL.