src/HOL/Library/Set_Algebras.thy

--- a/src/HOL/Library/Set_Algebras.thy	Sun Nov 02 17:16:01 2014 +0100
+++ b/src/HOL/Library/Set_Algebras.thy	Sun Nov 02 17:20:45 2014 +0100
@@ -2,7 +2,7 @@
     Author:     Jeremy Avigad and Kevin Donnelly; Florian Haftmann, TUM
 *)
 
-header {* Algebraic operations on sets *}
+section {* Algebraic operations on sets *}
 
 theory Set_Algebras
 imports Main