Nested Calculations - HP -16C Owner's Handbook Manual

Section 2: The Automatic Memory Stack 25
There are two functions, and [CLx], that disable stack lift—
that is, they do not provide for the lifting of the stack when the next
number is keyed in or recalled.* Following the execution of either of
these functions, a new number will simply write over the currently
displayed number instead of causing the stack to lift. (Although
the stack lifts when is pressed, it will not lift when the next
numberis keyed in or recalled.)
Tl1h| —|1h| —
Z|l2h| 5| 2h| 5
Y h| — h| —
X|ah| 5 |O0h| 5
Keys (g](CLx) A
LAST X =
As you can see, when an arithmetic operation is performed with
operands (A;q and 3,¢) in the X- and Y-registers, the stack drops
and the result (Dg) is left in the X-register.
For a complete listing of how functions affect stack lift (enabling,
disabling, and neutral) and digit entry, refer to appendix B.
Nested Calculations
The automatic stack lift and drop make it possible to do nested
calculations without using parentheses. Intermediate results are
automatically saved in the stack and used as needed. A nested
calculation is solved simply as a series of one- and two-number
operations. If you begin your calculation at the innermost number
or pair of parentheses and work outward (as you would when
working with pencil and paper), you will rarely need to store
intermediate results in a storage register.
* will also disable stack lift and clear the display (just as does) if digit entry has
been terminated. Otherwise, it is neutral to stack lift—that is, it neither enables nor
disables stack lift.