CONTRIBUTORS

--- a/CONTRIBUTORS	Wed Mar 24 21:17:19 2021 +0100
+++ b/CONTRIBUTORS	Thu Mar 25 08:52:15 2021 +0000
@@ -6,6 +6,9 @@
 Contributions to this Isabelle version
 --------------------------------------
 
+* March 2021: Florian Haftmann
+  Dedicated session for combinatorics.
+
 * March 2021: Simon Foster and Leo Freitas
   More symbol definitions for Z Notation: Isabelle fonts and LaTeX macros.