s updated out-of-place. Furthermore, the derivative of x at t is passed to the stepper. It is supposed to be used in the following way: <pre class="programlisting"> sys( in , dxdt , t );
 stepper.do_step( sys , in , dxdt , t , out , dt );
</pre>
<div class="note"><table border="0" summary="Note">
<tr>
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../../doc/src/images/note.png"></td>
<th align="left">Note</th>
</tr>
<tr><td align="left" valign="top"><p>This m