__builtin_cpow((0,0),(0,0))

[Ronny Peine]

Maybe i found something:

http://www.cs.berkeley.edu/~wkahan/ieee754status/ieee754.ps
page 9 says:

"A number of real expressions are sometimes implemented as INVALID
by mistake, or declared Undefined by illconsidered
language standards; a few examples are ...
0.0**0.0 = inf**0.0 = NaN**0.0 = 1.0, not Nan;"

I'm not really sure if he means that it should be 1.0 or it should be 
NaN but i think he means 1.0.

Ronny Peine wrote:
> Hi again,
> 
> a small example often used in mathematics and electronic engineering:
> 
> the geometric row ("Reihe" in german, i don't know the correct 
> expression in english):
> 
> sum from k=0 to +unlimited q^k = 1/(1-q) if |q|<1.
> this is also correct for q=0 where the sum gives q^0+q^1+q^2+...= 1 + 0 
> + 0 + ... (if 0^0 = 1) and 1/(1-q) = 1 too.
> I have read some parts in ieee 754 and articles about this but they say
> that 0^0 is very questionable, some say it's 0 some say it's 1.
> Well, after the standard there doesn't seem to be an accurate answer, in 
> mathematics it's 1 (and will always be 1).
> 
> cu,
> Ronny
> 
> Ronny Peine wrote:
> 
>> Well, these were math lectures (Analysis 1,2 and 3, Function Theory, 
>> Numerical Mathematics and so on). In every lectures it was defined as 
>> 1 and in most cases mathematical expressions are mostly tried to 
>> transform in equivalent calculations for the FPU (even though 
>> associativity is for example not preserved).
>>
>> I don't know of any standard which defines this to 0.
>>
>> Robert Dewar wrote:
>>
>>> Ronny Peine wrote:
>>>
>>>> Sorry for this, maybe i should sleep :) (It's 2 o'clock here)
>>>> But as i know of 0^0 is defined as 1 in every lecture i had so far.
>>>
>>>
>>>
>>>
>>> Were these math classes, or CS classes.
>>>
>>> Generally when you have a situation like this, where the value of
>>> the function is different depending on how you approach the limit,
>>> you prefer to simply say that the function is undefined at that
>>> point. As we have discussed, computers, which are not doing real
>>> arithmetic in any case, often extend domains for convenience, as
>>> in this case.
>>>
>>>
>>>
> 
>