HP HP-65 - Page 17

1134
Last-X Register. = Contains the value of x be-
fore the latest f(x) or f(x,y) was com-
puted. Used to: ® compute functions that
make multiple use of the same operand.
" enable recovery from keystroke errors
in certain instances. ® To Recall Last x,
See (138). = The following save
x in Last X before performing their func-
tions: [ = X =
[~ Note that
CLX does not affect the Last-X register.
135
Label (prefix). identifies its suffix (a
digit[0], . . .,[9], or top row key,[Y, - - - »
@) as a label in a stored program. A
branch to the part of the program thus
labelled can then be done by executing
followed by the same suffix. For user
defined functions, the label suffix must be
atop row key (I§, ..., @). ~
136
Natural Log (x) ([f prefix) or ex ([ prefix).
- “ W gives
error (blinking zero) if x is zero or nega-
tive. =