USAG.TXT File

                    (c)  Hewlett-Packard Company, 1990


OVERVIEW
--------

The USAG (usage) application enables you to review the stack argument
object type usage for any command built into the HP 48.


PROCEDURE
---------

Here's how to use USAG:

 1.  Transfer the USAG file from your computer to the HP 48.  The {USAG}
     menu label will show up in your HP 48 VAR menu.

 2.  Enter on stack level 1 a list containing a command name. 

 3.  Press the {USAG} menu key.  The HP 48 displays a screen with usage
     information for the command you specified in step 2.


EXAMPLE
-------

Assuming that you transferred the USAG program to your HP 48, that you entered
a list containing the COS command in level 1, and that you pressed {USAG} in
the VAR menu, here's the screen you get:

                              ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ Command or function
                              V                     identifier
  Command or         ÉÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ»  
  function name ÄÄÄÄ>º COS (Funct.)  ëS           º<ÄÄÄÄÄÄ Special
     ÚÄÄÄÄÄÄÄÄÄÄÄÄÄÄ>º #1 of 4                     º   function attributes
     ³               º                             º
  Argument type set  º                             º
  number             º                             º
        ÚÄÄÄÄÄÄÄÄÄÄÄ>º 1: Real Number              º
        ³            ÇÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄĶ
 Argument type set   º {NEXT}{PREV}{EXIT}          º<ÄÄÄÄÄÄ Menu labels
                     ÈÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍͼ
                                                    

This screen first tells you that COS is a function (all commands are either
RPN commands or functions).  Also, following the "(Funct.)" in your display
(indicated here by "ëS" ) there are three additional special function
attribute characters: (1) a down arrow, which indicates the function has an
inverse (for ISOL), (2) a derivative symbol, which indicates the function
has a derivative, and (3) an integral symbol, which indicates that you can
integrate the function.  These characters do not appear when the displayed
command does not have the corresponding properties.

The second line of the screen, showing "#1 of 4," tells you that there are
four possible combinations of argument types for COS, and that the first one is
currently displayed.  Like COS, some commands have only a few acceptable
combinations of argument types; others may have many more.

The next several lines of the USAG screen show the argument types accepted
by the command and their corresponding stack levels.  For COS you are first
shown that it can operate on a real number in level 1.  COS takes just one
argument, but for commands that require more, all the arguments are shown
on their appropriate stack levels.  Argument names match specific HP 48
object types.  (The exceptions are "Any," which means that all object
types are acceptable; "Symbolic," which means that the argument can be
an algebraic, a global name, or a local name; and "PICT".)

The menu keys at the bottom of the screen enable you to cycle forward
({NEXT}) and backward ({PREV}) through the argument type combinations.  As you
press {NEXT} and {PREV}, the second line of the display is updated, for
instance, to "#2 of 4", then "#3 of 4", and so on. The calculator beeps
when you step past the last argument type combination (back to the first), or
step backwards from first to last. When you want to exit the application, 
press {EXIT} or the [ATTN] key to return to the normal stack display.

If you use USAG to check the usage of a command that takes no arguments or
just one argument, the {NEXT}, {PREV}, and {EXIT} menu labels don't appear,
your current menu is left active.