">pendulum</span>
f1         <span class="string">torque</span> <span class="string">applied</span> <span class="string">to</span> <span class="string">inner</span> <span class="string">pendulum</span>
f2         <span class="string">torque</span> <span class="string">applied</span> <span class="string">to</span> <span class="string">outer</span> <span class="string">pendulum</span>
cost       <span class="string">cost</span> <span class="string">structure</span>
  .fcn     <span class="keyword">function</s