diff --git a/prism/include/DoubleVectorGlob.h b/prism/include/DoubleVectorGlob.h
new file mode 100644
index 00000000..66f5584d
--- /dev/null
+++ b/prism/include/DoubleVectorGlob.h
@@ -0,0 +1,36 @@
+//==============================================================================
+//	
+//	Copyright (c) 2002-
+//	Authors:
+//	* Dave Parker <david.parker@comlab.ox.ac.uk> (University of Oxford, formerly University of Birmingham)
+//	
+//------------------------------------------------------------------------------
+//	
+//	This file is part of PRISM.
+//	
+//	PRISM is free software; you can redistribute it and/or modify
+//	it under the terms of the GNU General Public License as published by
+//	the Free Software Foundation; either version 2 of the License, or
+//	(at your option) any later version.
+//	
+//	PRISM is distributed in the hope that it will be useful,
+//	but WITHOUT ANY WARRANTY; without even the implied warranty of
+//	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//	GNU General Public License for more details.
+//	
+//	You should have received a copy of the GNU General Public License
+//	along with PRISM; if not, write to the Free Software Foundation,
+//	Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//	
+//==============================================================================
+
+#include "PrismNativeGlob.h"
+
+//------------------------------------------------------------------------------
+
+// externs to global variables
+
+// cudd manager
+extern DdManager *ddman;
+
+//------------------------------------------------------------------------------