[om] OM Floats (XML Representation)

[Professor James Davenport]

On Mon, 8 Dec 2003, David Carlisle wrote:
> Richard Fateman wrote
> > Oh, you could also specify a radix, if you wanted to be "more
> > general".
> 
> OpenMath already contains CDs to encode floating point numbers in this
> way, as a structure just using integers specifying radix, precision,
> etc. (Mainly due to James)
 
> However it has always had a direct representation of IEEE doubles in
> addition to this, the question is just a technical one about how best to
> specify that representation using XML schema, not a suggestion to
> greatly change or drop the OpenMath representation of these objects.
Right, and the thing to note (as we said at the weekend, I recall) is that
xsd will say that, at XML level, NaN=NaN (where NaN is the specific 
representation that I thought you could say by <OMF NaN/>, but that 
doesn't seem to be in the standard). It will also say, that, at the XML 
level, any two hex representations are equal (even NaN-valued ones), but 
this implies nothing about an application. It certainly does not authorise 
replacement of one NaN by another.
James
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