public override object Evaluate (BaseIterator iter)
		{
			return (double) arg0.EvaluateNodeSet (iter).Count;
		}

		public override object Evaluate (BaseIterator iter)
		{
			IHasXmlNode xn = iter.Current as IHasXmlNode;
			if (xn == null)
				return String.Empty;
			XmlNode n = xn.GetNode ();
			if (n.OwnerDocument == null)
				return String.Empty;
			XmlDocumentType doctype = n.OwnerDocument.DocumentType;
			if (doctype == null)
				return String.Empty;
			XmlEntity ent = doctype.Entities.GetNamedItem (arg0.EvaluateString (iter)) as XmlEntity;
			if (ent == null)
				return String.Empty;
			return ent.SystemId != null ? ent.SystemId : String.Empty;
		}

		public override XPathResultType GetReturnType (BaseIterator iter)
		{
			return XPathResultType.Any;
		}

		public override bool EvaluateBoolean (BaseIterator iter)
		{
			if (arg0.GetReturnType (iter) == XPathResultType.NodeSet)
				return arg0.EvaluateBoolean (iter);
			
			return arg0.EvaluateNodeSet (iter).MoveNext ();
		}

		public static bool ToBoolean (BaseIterator iter)
		{
			return iter != null && iter.MoveNext ();
		}

		public override object Evaluate (BaseIterator iter)
		{
			return v.Evaluate (iter.NamespaceManager as XsltContext);
		}