--- a/thys2/Turing2.thy	Wed Jan 14 09:08:51 2015 +0000
+++ b/thys2/Turing2.thy	Wed Dec 19 16:10:58 2018 +0100
@@ -2,7 +2,7 @@
    Author: Jian Xu, Xingyuan Zhang, and Christian Urban
 *)
 
-header {* Turing Machines *}
+chapter {* Turing Machines *}
 
 theory Turing2
 imports Main