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

On Fri, 11 Jan 2008 13:29:35 +0200, Wolfgang Jeltsch wrote:

Am Freitag, 11. Januar 2008 10:54 schrieb Wilhelm B. Kloke:

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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

Wolfgang Jeltsch schrieb: that

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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.

This doesn’t matter. The Set data type I’m talking about would not know about NaN and would therefore allow multiple NaNs in a set.

This is a good thing because one can define natural numbers with such sets :-) ________ Information from NOD32 ________ This message was checked by NOD32 Antivirus System for Linux Mail Servers. part000.txt - is OK http://www.eset.com