Manual

Reverse Polish Notation (RPN) 51
Manipulating the stack
A number of stack-manipulation options are available. Most
appear as menu items across the bottom the screen. To see these
items, you must first select an item in history:
PICK Copies the selected item to stack level 1. The item below the one
that is copied is then highlighted. Thus if you tapped four
times, four consecutive items will be moved to the bottom four
stack levels (levels 1–4).
ROLL There are two roll commads:
• Tap to move the selected item to stack level 1. This is
similar to PICK, but PICK duplicates the item, with the
duplicate being placed on stack level1. However,
ROLL
doesn’t duplicate an item. It simply moves it.
• Tap to move the item on stack level 1 to the currently
highlighted level
Swap You can swap the position of the objects on stack level 1 with
those on stack level 2. Just press
o. The level of other objects
remains unchanged. Note that the entry line must not be active
at the time, otherwise a comma will be entered.
Stack Tapping displays further stack-manipulation tools.
DROPN Deletes all items in the stack from the highlighted item down to
and including the item on stack level 1. Items above the
highlighted item drop down to fill the levels of the deleted items.
If you just want to delete a single item from the stack, see “Delete
an item” below.