W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2002

Re: xsd:float and xsd:decimal

From: pat hayes <phayes@ai.uwf.edu>
Date: Sat, 30 Nov 2002 21:57:20 -0600
Message-Id: <p05111b0eba0f1fbb49f2@[10.0.100.247]>
To: Jan Grant <Jan.Grant@bristol.ac.uk>
Cc: w3c-rdfcore-wg@w3.org

>On 22 Nov 2002, Dan Connolly wrote:
>
>>  I'm somewhat surprised by this (my impression was that the value
>>  space of float was a bunch of open intervals around rationals
>>  or something), but after checking a bunch of details,
>>  I'm convinced.
>
>They're always points;

That is one account of what floats means, but there are others. I'm 
sure I recall one text from many years ago which defined floats in 
terms of intervals. Like I said, 'float'; isn't a mathematical term, 
and I don't think that there is a single definitive account of what 
exactly floats are supposed to mean.

>just the operators have been changed. (Otherwise
>it's hard to see how 1+1-1 = 1 with floats as open intervals.)

Define + on intervals by (a,b) + (c,d) = (a+b,c+d) and subtraction 
similarly. Multiplication is a bit more complicated, admittedly.

Pat

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Received on Saturday, 30 November 2002 23:53:36 EST

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