--- a/Journal/Paper.thy	Fri Feb 23 21:08:37 2018 +0000
+++ b/Journal/Paper.thy	Fri Feb 23 21:10:49 2018 +0000
@@ -2389,7 +2389,7 @@
   we received from anonymous referees. We are also deeply saddened about the
   tragic death of our co-author, colleague and friend, Chunhan, who
   suddenly died on 22 December 2016. He drove very much forward this work
-  and extended it in his PhD-thesis with a formal verification of an
+  and extended it in his PhD-thesis with a formal verification of a
   SELinux-style access control system. He was a stellar student
   and very promising young researcher in the field of interactive
   theorem proving. He was liked by many and indispensable for