[Cfp-interest 1930] Re: action item: suggest wording for hypot

[David Hough CFP]

> with that change, is the value of hypot(NaN, +-0) specified somewhere?

The general NaN rule applies in this case and so doesn't need to be 
repeated.    However, since hypot(NaN,inf) is unusual, maybe it should be
spelled out here:

 --- hypot(x, y), hypot(y, x), and hypot(x, -y) are equivalent.
 --- hypot(x, +-0) returns the absolute value of x, if x is not a NaN
 --- hypot(+-inf, y) returns +inf, even if y is a NaN.
 --- hypot(x, NaN) returns NaN if x is not +-inf.