var</var> will
be increasing; <code>downto</code> implies that they will be decreasing. 
The loop terminates when <var>var</var> passes the final value
(i.e. becomes smaller or larger than it, depending on the direction of
iteration); in other words, the loop body will never be executed for
values of <var>var</var> past the final value.  <code>below</code> and
<code>above</code> are similar to <code>to</code> and <code>downto</code>, except that
the loop terminates when <var>var</var> equals or passes the f