Prev Word   (Motif environment only)
  Moves the cursor a word at a time in the reverse direction.
  Steps:
     1.  Press the Prev Word key (CTRL/LEFT)
  Usage notes:
  o  Prev Word always moves to the start of the current or previous word, if
     any.
  o  The start of a word is the first non-white space character.  A series
     of tabs, or tabs and spaces, is not treated as separate words.
  o  With the WPS keypad, CTRL/LEFT continues a case change as follows:
     1.  Press the WPS Lower Case key (GOLD-KP3) or WPS Upper Case
         key (KP3) to change the case of the current character.
     2.  Press CTRL/LEFT to continue the case change to the start of the
         previous word.
  o  Motif function keys are on by default on Motif DECwindows.
  Related topics:
     CHANGE DIRECTION     END OF LINE     START OF LINE
     SET FUNCTION KEYS MOTIF