the unary negation operator is not the same as subtraction. A basic flaw
in your argument.

Your mnenonic is incomplete. How would you express a negative number in
an equation?

the second flaw is that you attribute the syntax used in writing formulas in
Excel to be synonymous to hand written formulas. But it isn't - it is a
syntax defined by the authors of Excel. Excel defines a set of rules for
its syntax which, to increase comfort, to a large extent parallels hand
written formulas, but nonetheless, it is a syntax defined by the creators of
excel. It is thus incumbent on the user to understand that syntax; not make
assumptions.

--
Regards,
Tom Ogilvy


"fred" wrote in message
...
Well, yes, that is basically the same thing a couple of my friends said.
But none of them are mathematicians. The only thing about it is that
that's
not how math/algebra/calculus/etc. is done. Negation and subtraction are
one-in-the-same to the best of my somewhat-in-depth knowledge. There's
even
the mnemonic device "Please Excuse My Dear Aunt Sally" to help remember
the
order in which operations are supposed to be executed (Parenthesis,
Exponents, Multipication, Division, Addition, Subtraction).

To me the only valid argument, based on different priorities, is that
non-math-people, when using actual numbers, not cell references, expected
=-5^2 to be "negative five, squared". And they wanted to satisfy the
secretaries and bean counters, not the heavy-duty math people.

However, having done software development myself, I think it most likely
that it's just a bug and just hasn't been fixed yet. In fact, to me,
putting in a zero and getting a different answer proves it's wrong.


"Alan" wrote in message
...
"fred" wrote in message
...


Are they rewriting math rules now? ... negation is different from
subtracting? Indeed! Not in any math book I've ever seen.


This is an interesting point.

I guess I tend to view the two things as being separate and different
in nature.

Negation (in the sense that I believe you are using it above) such as
turning +5 into -5 'creates' a new number. The value of that number
is -5.

Subtraction is an operation performed on one value with another.
Therefore, subtracting +5 from a value is a different thing.

I guess where this becomes important is in the example used elsewhere
in this thread of:

=-5^2

It could be argued that it is quite valid for either answer (+25
or -25) to be correct depending on whether we are squaring -5 or
whether we are (implicitly) subtracting 5^2 from (the implicit) 0 that
is not shown.

If we put the zero in:

=0-5^2

then I would suggest that the *only* valid interpretation is that we
are subtracting 5^2 from zero, and thus the answer *must* be -25.

Given that excel must have rules, it does not seem unreasonable for
the algorithms to require an explicit subtraction, else go with the
interpretation that we are squaring -5.


Having said all of that, if we don't bother to use brackets to make
the calculations completely explicit and unambiguous, then I guess we
are each *choosing* to take the risk - whether we know it or not.

Does my thinking sound reasonable?


Alan.