| Date: Tue, 19 Jun 2007 00:47:13 -0400 | From: Arthur Smyles <[EMAIL PROTECTED]> | | 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. _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
