(12C) Signum Function

[rprosperi]

(03-03-2019 05:51 PM)Dieter Wrote:  I wonder what happens in similar cases like

2 [+] [√x] [=]
or
5 [x] [LN] [x²] [=]

I'd expect 3,41 and 12,95 but obviously you never know...

Your expectations are correct, IMHO.

Original 12CP: 3,41 & 12,95

Later 12CP: 1,41 & 2,59

I've not researched yet, but Gerson's summary "...arguments on the display cannot be reused after an operator..." seems a concise summary of the 'fixed' or at least updated, behavior. Denying re-use of the original argument may have been necessary (or at least easier) as a result of adding the UNDO feature in the 2nd and all later series of 12CP models.

One could argue either way which is 'right', since algebraic notation is notoriously ambiguous, though I must admit that this is a more interesting than normal situation.

@Gerson - of course the RPN solution works; they're always unambiguous.