diff --git a/tut6/src/BoolTreeNode.java b/tut6/src/BoolTreeNode.java
index c5ba654..0cf7902 100644
--- a/tut6/src/BoolTreeNode.java
+++ b/tut6/src/BoolTreeNode.java
@@ -126,7 +126,7 @@ public class BoolTreeNode
 		
 		// negationsknoten
 		if (!child1.isNegation())
-			return false;
+			return child1.removeDoubleNegations();
 		BoolTreeNode grandchild = child1.child1;
 		variable = grandchild.variable;
 		child1 = grandchild.child1;