HP 50g Graphing Calculator - Manual (Page 787)

Page 27-5
Viewing variables and selecting units
After you select a subject and title, you can view the catalog of names,
descriptions, and units for the variables in the equation set by pressing
#VARS#.
The table below summarizes the operations available to you in the Variable
catalogs.
Operations in Variable catalogs
Viewing the picture
After you select a subject and title, you can view the picture of the problem (if
the title has a picture).
To see the picture, press @#PIC#@. While the picture is displayed, you can:
Key Action
L Toggles between the catalog of descriptions and the catalog
of units.
#!#SI##
@ENGL#
Makes SI or English units active, unless this conflicts with the
units already defined for an existing (global) variable. Purge
existing variables (or enter the specific units) to eliminate
conflicts.
!UNITS
Toggles between units used and units not used.
Creates or changes all equation variables to have indicated
unit type and usage.
#PURG#
Purges all equation variables for this title in the current
directory. This also eliminates SI vs. English units conflicts.