content: import matplotlib
  import matplotlib.pyplot as plt
  fig = plt.figure()
  ax = fig.add_subplot(111)
  patch1 = matplotlib.patches.Circle(
      [0.5,0.5],0.05
  )
  patch2 = matplotlib.patches.Rectangle(
      [0.3,0.3],0.4, 0.4, alpha=0.5, 
      fill=False, edgecolor='black',
      linestyle = '--'
  )
  arrow1 = matplotlib.patches.Arrow(
      0, 0.5,0.45,0, width=0.05,
      color='black'
  )
  arrow2 = matplotlib.patches.Arrow(
      0.55, 0.5,0.45,0, width=0.05,
      color='black'
  )
  line1 = matplotlib.lines.Line2D(
      [0.5,0.5], [0,0.45],
      linestyle='--', color='black'
  )
  text1 = matplotlib.text.Text(
      0, 0.45, '$n_{A0}$\n$V_0$\n$U_A=0$'
  )
  text2 = matplotlib.text.Text(
      0.8, 0.45, '$n_{A1}$\n$V_1$\n$U_{A1}$'
  )
  for artist in [
      patch1,patch2,arrow1,arrow2,
      line1,text1,text2
  ]:
      ax.add_artist(artist)
  ax.set_frame_on(False)
  ax.set_axis_off()
  ax.set_aspect(1.0)
  
  fig.
  
  
  fig = plt.figure()
  ax = fig.add_subplot(111)
  patch1 = matplotlib.patches.Circle(
      [0.5,0.5],0.05
  )
  patch2 = matplotlib.patches.Rectangle(
      [0.3,0.3],0.4, 0.4, alpha=0.5, 
      fill=False, edgecolor='black',
      linestyle = '--'
  )
  arrow1 = matplotlib.patches.Arrow(
      0, 0.5,0.45,0, width=0.05,
      color='black'
  )
  arrow2 = matplotlib.patches.Arrow(
      0.55, 0.5,0.45,0, width=0.05,
      color='black'
  )
  arrow3 = matplotlib.patches.Arrow(
      0.5, 0.0, 0,0.45, width=0.05,
      color='black'
  )
  text1 = matplotlib.text.Text(
      0, 0.45, '$n_{A0}$\n$V_0$\n$U_A=0$'
  )
  text2 = matplotlib.text.Text(
      0.8, 0.45, '$n_{A1}$\n$V_1$\n$U_{A1}$'
  )
  text3 = matplotlib.text.Text(
      0.55, 0.1, '$n_{Ar}$\n$V_r$'
  )
  for artist in [
      patch1,patch2,arrow1,arrow2,
      arrow3,text1,text2,text3
  ]:
      ax.add_artist(artist)
  ax.set_frame_on(False)
  ax.set_axis_off()
  ax.set_aspect(1.0)