special">)</span></code>
        (there are exceptions for some special routines). So, even if there is no
        explicit time dependence, one has to define <code class="computeroutput"><span class="identifier">t</span></code>
        as a function parameter.
      </p>
<p>
        Now, we have to define the initial state from which the integration should
        start:
      </p>
<p>
</p>
<pre class="programlisting"><span class="identifier">state_type</span> <span class="identifier">x</span><span class="