span class="c1"># print(&#39;x21\n&#39;, x21)</span>
                <span class="c1"># print(&#39;x22\n&#39;, x22)</span>
                <span class="n">x11</span><span class="p">,</span> <span class="n">x12</span><span class="p">,</span> <span class="n">x21</span><span class="p">,</span> <span class="n">x22</span><span class="p">,</span> <span class="n">theta</span><span class="p">,</span> <span class="n">u1</span><span class="p">,</span> <span class="n">u2</span><span class="p">,</span> <span class="n">