[cfp-interest 3511] Re: hypot(x, y) - C2Y F.10.5.4

[Damian McGuckin]

On Thu, 5 Jun 2025, Vincent Lefevre wrote:

> On 2025-06-05 16:13:39 +1000, Damian McGuckin wrote:
>>
>> In the latest draft,  the first item of paragraph 1 says
>>
>> 	hypot (x, y), hypot (y, x), and hypot (x, -y) are equivalent.
>>
>> Is that complete?
>
> I think so.

I should see if we can use the 'equivalent to' symbol.

>> 	hypot(+/- x, +/- y) = hypot(|x|, |y|) = hypot(|y|, |x|)
>
> The "=" is correct only when the result is not a NaN.
>
> BTW, "hypot(+/-inf, y) returns +inf, even if y is a NaN" should
> be "[...] even if y is a quiet NaN".

Annex F.2.2 explicitly says that it uses the term NaN to refer to a quiet 
NaN unless explicitly mentioned otherwise. I depends on what is meant by 
the word+identifier(s) combination of 'all x' or 'all y' or 'all x,y'.

> Similarly, in F.10.5.5 about pow, "for any {y,x}, even a NaN"
> should be "[...], even a quiet NaN". Or like F.10.5.6 (pown):
> "for all {y,x} not a signaling NaN".

Hmmmm.  Food for thought.

Thanks for your time Vincent - Damian