line equation.</td>
    </tr>
   <tr id="#1">
      <td style="text-align:right;">1</td>
      <td style="text-align:center;">&#128522;</td>
      <td style="text-align:left;">$\varphi$</td>
      <td style="text-align:left;"><p><eq><span class="katex"><span class="katex-mathml"><math><semantics><mrow><mi>φ</mi></mrow><annotation encoding="application/x-tex">\varphi</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="strut" style="height:0.43056em;"></span><span c