20.4  88 

     1.  15-Jan-1988 - Added expression parsing.  This allows you to enter
         an arithmetic expression wherever a number is  called  for.   The
         syntax  is  <expression>.  See TOPDRAWER DATA EXPRESSION for more
         details.  Added REPEAT and ENDREPEAT commands.  The  equals  sign
         "="  may  not be replaced by a comma "," or slash "/" where it is
         used in the documentation.  It may be replaced by spaces.   Plus,
         or  minus "+-" signs are not allowed in options except as part of
         a number.
     2.  4-Feb-1988 - Added angle lexicals (VIEW_...).  Fixed some bugs in
         MESH plots.  Added X="expression"  command.   Added  CREATE  MESH
         command  to  create  mesh  data sets.  Modified PLOT VARIABLE for
         mesh data so the symbol size is automatically set to the  maximum
         bin size.
     3.  Apr-1988  - Fixed LIMITED option for SHOW DATA command, and added
         LIMITED option to BIN command.  Added FOR option to WAIT.   Added
         PACKED  option  to  SET ORDER.   The  SET  ORDER  and SET STORAGE
         commands no longer delete data.  The SORT command has been added.
     4.  Jun-1988   -  Fixed  the  error  calculation  on  MEAN  for  show
         statistics.  Fixed NEW RESET so that scales are also reset to the
         original default.
     5.  Aug-1988 - Added MESH,NORMAL options to BIN command.  Added CHECK
         option to  ADD,SUBTRACT,MULTIPLY,DIVIDE  commands.   Added  SPLIT
         option  to  PROJECT  command.  Added ADD,SUBTRACT,MULTIPLY,DIVIDE
         options to DEFINE HISTOGRAM commnand.   Fixed  an  infinite  loop
         when a single point is histogrammed.
     6.  Nov-1988  -  Added  THETA,PHI,ANGLE specifications to SET SYMBOL,
         and SET GRID.  Spiffed up the show formats.   Added  EXCL  driver
         for native mode support of TALARIS-1590 and LN-03+ printers.
     7.  Dec-1988  -  Fixed several bugs.  Set window 3 of -4 did not work
         as the first window.  Only 1 of 4 could be the first  window.   A
         call  to  t2MAIN  with  blank  string after a call with non blank
         string  would  not  prompt  for  input.    SHOW   WINDOW   worked
         incorrectly   for   -   windows.    Calls   to  T2JOIN,T2HIST...,
         incorrectly reset permanent limits.
     8.  Dec-1988  -  Added  NTFIT,NPFIT  lexicals,  and  extended  TDPLT,
         T2JOIN,T2HIST for 3-d data.
     9.  28-Dec-1988              -              Added             options
         AREA/SHARE/SAVE/READ/WRITE/INPUT/OUTPUT    to     SET/DEFINE/SHOW
         HISTOGRAM commands.  Created a compatible version with HBOOK4.