CONTRIBUTORS

--- a/CONTRIBUTORS	Wed Feb 22 19:59:06 2012 +0100
+++ b/CONTRIBUTORS	Thu Feb 23 08:17:22 2012 +0100
@@ -6,6 +6,9 @@
 Contributions to this Isabelle version
 --------------------------------------
 
+* January 2011: Florian Haftmann, TUM, et. al.
+  (Re-)Introduction of the "set" type constructor.
+
 
 Contributions to Isabelle2011-1
 -------------------------------