Margins applied to display:table elements

Assume the following XML fragment:

   <CONTAINER>
      <TABLE>
	<CELL> Hello </CELL>
      </TABLE>
   </CONTAINER>

Assume the following CSS:

   CONTAINER { direction: ltr; }
   TABLE { display: table; margin: 4em auto; }

What will the width of the table be?


As far as I can tell from the CSS2 spec, the margin-right value will
be treated as auto.

So: How can one specify that the TABLE must span the width of the
CONTAINER, with 4em margins on either side, without changing the padding
or width of the CONTAINER or adding other elements?

-- 
Ian Hickson