title: Python, How to fill between multiple (4) curves?
body: <pre><code>fig = plt.figure(num=1)
  ax=fig.add_subplot(111)
  
  def f1(x):
      return 1/x
  def f2(x):
    return 2/x
  def f3(x):
    return np.sqrt(x**2-1)
  def f4(x):
    return np.sqrt(x**2-2)
  s= np.arange(np.sqrt(2),5,0.05)
  t=np.arange(1,5,0.05)
  y1=f1(t)
  y2=f2(t)
  y3=f3(t)
  y4=f4(s)
  ax.plot(t,y1,'k-',t,y2,'k-',t,y3,'k-',s,y4,'k-')
  plt.xlim([1.1,2.1])
  plt.ylim([0.5,1.5])
  plt.show()
  </code></pre>
  
  <p>I would like to fill the area between the curves described by those four functions. Not sure how to use the <code>fill_between</code> option in this case.</p>