1      At many places in the Tutorial, it will be appropriate for you to
 2 practice what you are learning.  To do this, wait until the "cursor" has
 3 returned to the menu portion of the terminal screen and then press function
 4 key F2.  If your keyboard doesn't have function keys, use the ESC key followed
 5 by the letter c.  This will take you out of the Tutorial temporarily and put
 6 you at "command level," where you can carry out the instructions you've been
 7 given.
 8 
 9      Command level is indicated by a "ready message," which in this case will
10 look like this:
11 
12 r 18:29 24.722 821 level 2
13 
14 The cursor will be positioned one or two lines beneath the ready message for
15 you to begin practicing.  When you are finished practicing and ready to
16 reenter the Tutorial, type the letters pi immediately below a ready message
17 and then press RETURN.