Re: [Scheme-reports] multiple NaN values

[John Cowan <cowan@x>]

Per Bothner scripsit:

> IEEE 754 specifies multiple NaN values.  Scheme generally does
> not care if there is a single value (bit pattern) for NaN,
> or if there are multiple values:  If there are multiple NaN
> values, or just one, they are all equivalent in terms of Scheme
> computation.

Added.

> If there are multiple NaN values, they are all =.

This is not the case: NaN is not = to any number, not even NaN.

> However, the eqv? function is permitted (but not required)
> to return #f when given two different NaN values.

This is the subject of http://trac.sacrideo.us/wg/ticket/229 , which
will be part of the upcoming fifth ballot.

-- 
I suggest you solicit aid of my followers       John Cowan
or learn the difficult art of mud-breathing.    cowan@x
        --Great-Souled Sam                      http://www.ccil.org/~cowan

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