CONTRIBUTORS

--- a/CONTRIBUTORS	Mon Dec 28 22:40:01 2020 +0100
+++ b/CONTRIBUTORS	Tue Dec 29 16:42:01 2020 +0100
@@ -6,6 +6,9 @@
 Contributions to Isabelle2021
 -----------------------------
 
+* December 2020: Stepan Holub
+  Contributed lemmas for List
+
 * December 2020: Martin Desharnais
   Zipperposition 2.0 as external prover for Sledgehammer.