CONTRIBUTORS

--- a/CONTRIBUTORS	Fri Dec 04 13:24:49 2020 +0100
+++ b/CONTRIBUTORS	Fri Dec 04 15:07:47 2020 +0100
@@ -5,6 +5,9 @@
 
 Contributions to this Isabelle version
 --------------------------------------
+* December 2020 Walter Guttmann
+  Extension of session HOL/Hoare with total correctness proof system
+
 * November 2020: Stepan Holub
   Removed preconditions from lemma comm_append_are_replicate