Re: [boost] The meaning of -nan (was [serialization] facets for non-finite numbers)

Paul A Bristow wrote:

| Paul Bristow wrote | > That is indeed the *intention* - but entirely USER-DEFINED | and with NO MATH | > MEANING. | > | > NaNs are never > < or == anyway? | | But it tells you where how you got there doesnt it?

Maybe - but this is getting OT - the topic was Octonionic Not-A-Numbers ;-)

Is this really off-topic? I've seen everyone assert that -nan has no mathematical meaning. Does this mean that there is no pfficial specification (whether it is "mathematically meaningful" or not) of how a -nan can arise as a result of an arithmetic operation?