HP 39gs Master Manual page 335

iv.
SHIFT
Pressing
SHIFT
highlighted/selected branch for the one on the immediate
left.
For example, suppose you have selected the middle term
and then extended the selection using
right:
... then pressing
The main use for this is when you want to substitute a
previous result into a new expression but the terms are not in
the right order to do so. See page 352 for an example of this (specifically part 5 of the
example).
In-line editing mode
If you find that you are not able to edit part of an expression in exactly
the way you need, or if you have entered an operation at the wrong
level and are having trouble removing it, then you can highlight and edit
an expression 'in-line' as if you were entering it in the calculator's
normal view.
HOME
For example, highlight part of an expression as shown right. Now press
SK1 ( ) and choose 'Edit expr.' from the menu. You can now
perform any editing you require and the result will be inserted into the
full expression at that point.
Cursor mode
Cursor mode can be used to select portions of an expression by drawing
a box around it. From the
arrow keys to move a cursor around on the screen. As you do so it
places a box around different parts of the expression that are selectable.
Press to select that section. Unfortunately, it is sometimes not as
ENTER
easy as it looks to select just that small portion of the entire expression.
swaps the currently
SHIFT
will result in:
SHIFT
menu, select 'Cursor mode'. Use the
as shown
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