diff -r a75d71c73362 -r 9f90ac19e32b src/HOL/Library/Boolean_Algebra.thy
--- a/src/HOL/Library/Boolean_Algebra.thy	Thu Jun 26 10:06:54 2008 +0200
+++ b/src/HOL/Library/Boolean_Algebra.thy	Thu Jun 26 10:07:01 2008 +0200
@@ -8,7 +8,7 @@
 header {* Boolean Algebras *}
 
 theory Boolean_Algebra
-imports ATP_Linkup
+imports Plain
 begin
 
 locale boolean =