[om] comparing OM Floats (XML Representation)

Professor James Davenport jhd at cs.bath.ac.uk
Sun Nov 30 18:47:02 CET 2003

On Sat, 29 Nov 2003, Richard Fateman wrote:
> If you want to use IEEE floats, then the rules for equality
> (etc) are all pretty much defined.  You may wish to distinguish
They are defined by IEEE: it is XML that seems to be the problem.
Probably OpenMath here should ignore XML (for us, after all, it is only an 
> (as does Common Lisp) several kinds of equality.
> EQ  equality means  "same objects".  This is like address comparison.
> EQL  means isomorphic  (think of it as 'printing the same').
> = means numeric equality in which 0.0e0 = 0 = 0.0d0 = #c(0 0)  [complex 
> number]
> In the case of floats, you might do this:
> (setf x (make-a-NaN))
> (EQ x x) --> true
> (=  x x) --> false
> NaNs are unordered with respect to each other or floats,
> and anyone who tries to impose an ordering is in for trouble.
Indeed so. 
> Richard Fateman
> a voting member of the IEEE 754 committee.
Now is only you wer a voting member of W3C...

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