if(lval.getLength() == 0 || rval.getLength() == 0) return Sequence.EMPTY_SEQUENCE;
	public Sequence eval(Sequence contextSequence, Item contextItem)		throws XPathException {			Sequence lval = left.eval(contextSequence, contextItem);			Sequence rval = right.eval(contextSequence, contextItem);			if(!(Type.subTypeOf(lval.getItemType(), Type.NODE) && Type.subTypeOf(rval.getItemType(), Type.NODE)))				throw new XPathException("intersect operand is not a node sequence");			NodeSet result = lval.toNodeSet().intersection(rval.toNodeSet());			return result;	}