HP HP-28S - Page 54

In preparation, create a variable so you have something to rename-a
variable A with value 10.
Put the value 10 on the stack.
10
I ENTER I
Create the variable A.
~ A ISTOI
3: 133
2: 151
1: 10
------
3: 133
2: 133
1: 151
-------
Note that A appears in the USER menu.
Suppose you want to rename A to B. Put the old name on the stack.
~ A I ENTER I 3: 133
2: 151
Put the new name on the stack.
~ B I ENTER I
1: I A I
-------
3: 151
2: I A I
1: I B I
-------
This completes the preparation: the variable exists, the old name is on
the stack, and the new name is on the stack. The old and new names
are the arguments to the program-the program will assume they're
on the stack in this order. The steps that follow are those that will be
in the program.
The steps include
three common stack-manipulation commands,
OVER, ROT, and SWAP. You'll see how they work as you execute the
steps.
Copy the old name to level 1. (Use the OVER command in the STACK
menu.)
.1 STACK lOVER
3: I A'
2: I B I
1: I A I
DDlIli:WDD![f:IID[f;IIIDIIDDl
3: Using Variables 53
I