src/HOL/Basic_BNFs.thy

--- a/src/HOL/Basic_BNFs.thy	Sat Jul 18 21:44:18 2015 +0200
+++ b/src/HOL/Basic_BNFs.thy	Sat Jul 18 22:58:50 2015 +0200
@@ -7,7 +7,7 @@
 Registration of basic types as bounded natural functors.
 *)
 
-section {* Registration of Basic Types as Bounded Natural Functors *}
+section \<open>Registration of Basic Types as Bounded Natural Functors\<close>
 
 theory Basic_BNFs
 imports BNF_Def