Figure 6

a.
Enter Action Code (? for help): r

   Enter string: black

   Node removed

Enter Action Code (? for help): p

      1 brown      L: -          R: cherry
      2 cherry     L: -          R: -
      3 green      L: brown      R: red
      4 red        L: -          R: -

b.
           green             (1)
         /       \
    brown         red        (2)
        \
       cherry                (3)