HP 50G, User Manual

Page: 690 / 887

Page 21-43
Press
@@@OK@@@
to cancel message box output.
Message box output without units
Let’s modify the program
@@@p@@@
once more to eliminate the use of units
throughout it. The unit-less program will look like this:
«
“
Enter V,T,n [S.I.]:
“
{
“
:V: :T: :n:
“
{2 0} V }
INPUT OBJ
→ →
V T n
«
V DTAG T DTAG n DTAG
→
V T n
«
“
V=
”
V
→
STR +
“ ”
+
“
T=
”
T
→
STR +
“ ”
+
“
n=
”
n
→
STR +
“ ”
+
‘
8.31451*n*T/V
‘
EVAL
→
STR
“
p=
”
SWAP + + + + MSGBOX
» » »
And when run with the input data V = 0.01, T = 300, and n = 0.8, produces
the message box output:
Press
@@@OK@@@
to cancel the message box output.
Relational and logical operators
So far we have worked mainly with sequential programs. The User RPL
language provides statements that allow branching and looping of the program
flow. Many of these make decisions based on whether a logical statement is
true or not. In this section we present some of the elements used to construct
such logical statements, namely, relational and logical operators.
Relational operators
Relational operators are those operators used to compare the relative position
of two objects. For example, dealing with real numbers only, relational