Re: [Haskell-cafe] 0/0 > 1 == False

cristi:

On Thu, 10 Jan 2008 10:22:03 +0200, Mitar wrote:

...

Hi!

Why is 0/0 (which is NaN) > 1 == False and at the same time 0/0 < 1 == False. This means that 0/0 == 1? No, because also 0/0 == 1 == False.

I understand that proper mathematical behavior would be that as 0/0 is mathematically undefined that 0/0 cannot be even compared to 1.

There is probably an implementation reason behind it, but do we really want such "hidden" behavior? Would not it be better to throw some kind of an error?

NaN is not 'undefined'

(0/0) /= (0/0) is True (0/0) == (0/0) is False

You can use these to test for NaN.

You can also use isNaN :) Prelude> isNaN (1/0) False Prelude> isNaN (0/0) True -- Don