span style="margin:15px; ">x<sub>2</sub><sup>2</sup></span>
    <span style="margin:15px; ">x<sub>1</sub>x<sub>2</sub></span>
    <span style="margin:15px; ">|x<sub>1</sub> - x<sub>2</sub>|</span>
    <span style="margin:15px; ">|x<sub>1</sub> + x<sub>2</sub>|</span>
  </div>
  <div>
    <label for="k">&#934;<sub>0</sub>to &#934;<sub>k</sub> k=</label>
    <input type="text" name="k" id="k" value="3" size="3">
  </div>
  <div>
    <button id="run_lr">Linear Regression</button>
    <button id="run_lr_reg">Li