On Mon, Oct 08, 2012 at 04:39:52PM -0400, Ned Batchelder wrote:
"In accordance with the IEEE 754 standard, when NaNs are compared to any value, even another NaN, the result is always False, regardless of the comparison. This is because NaN represents an unknown result. There is no way to know the relationship between an unknown result and any other result, especially another unknown one. Even comparing a NaN to itself always produces False."
1) It is not the case that NaN <comp> NaN is always false.
2) "invalid result" is more appropriate than "unknown result".