I have a table containing coordinates and I want to insert these into  
another table, converting them to boxes.
	I would like to use the same syntax as arrays :
	INSERT INTO ... (coords) SELECT ARRAY[a,b,c] FROM ...
	But I want boxes. Is there a way to do this ?
	SELECT BOX[[a,b],[c,d]] FROM ...
	raises a Syntax Error.
	And I'd like to avoid to concatenate strings to build a box  
representation like
	'((1,2),(3,4))'::box;
	Is there a way ?
	Thanks !