src/HOL/Isar_Examples/Group.thy

--- a/src/HOL/Isar_Examples/Group.thy	Tue Aug 02 18:45:34 2016 +0200
+++ b/src/HOL/Isar_Examples/Group.thy	Tue Aug 02 18:46:24 2016 +0200
@@ -5,7 +5,7 @@
 section \<open>Basic group theory\<close>
 
 theory Group
-imports Main
+  imports Main
 begin
 
 subsection \<open>Groups and calculational reasoning\<close>