--- a/src/HOL/Isar_Examples/Summation.thy Tue Aug 02 18:13:24 2016 +0200
+++ b/src/HOL/Isar_Examples/Summation.thy Tue Aug 02 18:44:37 2016 +0200
@@ -5,7 +5,7 @@
section \<open>Summing natural numbers\<close>
theory Summation
-imports Main
+ imports Main
begin
text \<open>