l">(</span><span class="identifier">System</span> system<span class="special">,</span> <span class="identifier">State</span> <span class="special">&amp;</span> start_state<span class="special">,</span> <span class="identifier">Time</span> start_time<span class="special">,</span> 
                         <span class="identifier">Time</span> end_time<span class="special">,</span> <span class="identifier">Time</span> dt<span class="special">,</span> <span class="identifier">Observer</span> observer<span class