[Haskell-cafe] Re: Why purely in haskell?

[Wilhelm B. Kloke]

Wolfgang Jeltsch <g9ks157k at acme.softbase.org> schrieb:
>
> However, the fact that (0 / 0) == (0 / 0) yields False is quite shocking.  It 
> doesn?t adhere to any meaningful axiom set for Eq.  So I think that this 
> behavior should be changed.  Think of a set implementation which uses (==) to 
> compare set elements for equality.  The NaN behavior would break this 
> implementation since it would allow for sets which contain NaN multiple 
> times.

You forget, that the intention of NaN is denial of membership of any set of
numbers.
-- 
Dipl.-Math. Wilhelm Bernhard Kloke
Institut fuer Arbeitsphysiologie an der Universitaet Dortmund
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