*2.7: news.*

**adda**/math/unary not always taking precedence:. negation has the same precedence as

multiplication and division;

because, negation means mult by -1.

So -a^b should be -1*a^b = -(a^b).

details:

. programmers were accustomed to the C language,

in which unary operators such as negation

have higher precedence than any binary operator;

(and there was no exponent operator in C

to cause them to think twice about the matter).

so, when programmers use an exponent operator,

they may have wished to remain consistent with C;

however, for centuries,

the polynomial -x^2

has meant -1*x^2 = -(x^2)

not (-x)^2 = x^2 .

. look at the

**HP48G User Guide/order of operations:**

**priority#1:**

Prefix functions (such as sin, ln, ...)

and Postfix functions (such as ! (factorial)).

--[. many could say negation is a prefix -();

*2.16:*nevertheless,

notice the way math has superscripted powers

(rather than using an operator);

as if it was an extension of the symbol's name

like the way subscripts actually are,

and thus intuitively having higher precedence

than any operation applied to the name .]

**priority#2**: Power (^) and square root.

**priority#3**: Negation (-), multiplication, and division.

--[. here is the 2nd place -() fits;

but, only because of its equvalence to -1*();

many think it's obvious that the negative

is part of the number's value .]

**priority#4**: Addition and subtraction.

. clarity should take precedence over correctness;

so, the system needs to ask new users

-- at least those who use the form (-x^n):

"( how would you eval -2^2 ?. furthermore, when exporting adda`binary,

{ 4, -4 } ??

. -1*2^2 is definitely = -1(2^2) = -4 .

whereas (-2)^2 = (-2)(-2) = 4 . )

or allowing copies to text

always write it unambiguously { -(2^2), (-2)^2 }.