# Undo And Cmd Functions; Choose Boxes Vs. Soft Menu - HP 49g+ User Manual

Graphing calculator.

To delete two variables simultaneously, say variables R and Q, first create a
list (in RPN mode, the elements of the list need not be separated by commas
as in Algebraic mode):
J „ ä ³
™ ³
`
@ @ @ R ! @ @
@ @ @ Q ! @ @
Then, press
use to purge the variables.
I
@ P U R G E @
Additional information on variable manipulation is available in Chapter 2 of
the calculator's User's Guide.

## UNDO and CMD functions

Functions UNDO and CMD are useful for recovering recent commands, or to
revert an operation if a mistake was made. These functions are associated
‚ ¯
with the HIST key: UNDO results from the keystroke sequence
, while
„ ®
CMD results from the keystroke sequence
.

### CHOOSE boxes vs. Soft MENU

In some of the exercises presented in this chapter we have seen menu lists of
commands displayed in the screen. This menu lists are referred to as
CHOOSE boxes. Herein we indicate the way to change from CHOSE boxes
to Soft MENUs, and vice versa, through an exercise.
Although not applied to a specific example, the present exercise shows the
two options for menus in the calculator (CHOOSE boxes and soft MENUs). In
this exercise, we use the ORDER command to reorder variables in a directory,
we use:
„ ° ˜
Show PROG menu list and select MEMORY
Page 2-17