| Date: Tue, 19 Jun 2007 00:47:13 -0400
| From: Arthur Smyles <atsmyles at rcn.com>
|
| According to Section 2.4 Infinities and NaNs?
|
| "A NaN is regarded as a real (but not rational) number whose value
| is so indeterminate that it might represent any real number,
| including positive or negative infinity, and might even be greater
| than positive infinity or less than negative infinity."
|
| In formal comment 11, Aubrey Jaffer correctly stated that NaN is
| not a real number. But, his conclusion that a NaN is a complex
| number is also incorrect. The complex numbers includes the set of
| all real and imaginary numbers. NaN is neither real nor imaginary,
| therefore it cannot be a value in the real or the imaginary part of
| a complex number, therefore it cannot be complex. So the
| definition of a number is really the set of all complex numbers and
| NaN.
The argument naming conventions have `z' for complex arguments. If
NaN is not complex, then the `z' convention must be changed to be:
complex number or NaN.
A similar situation exists for +inf.0, -inf.0 and real numbers.
Do you consider +inf.0 and -inf.0 to be real numbers?
| If you treat a NaN as a number that is not complex, it will solve
| the performance issues stated in formal comment 143. It will also
| address formal comment 230, which will make reals conform to
| mathematical usage. It will also conform with IEEE-754.
|
| In conclusion this section should read:
|
| A NaN is regarded as a number that is not complex.
Received on Thu Jun 21 2007 - 22:15:26 UTC