- From: Pat Hayes <phayes@ihmc.us>
- Date: Wed, 20 May 2009 12:25:33 -0500
- To: "Boris Motik" <boris.motik@comlab.ox.ac.uk>
- Cc: "'Eric Prud'hommeaux'" <eric@w3.org>, "'Seaborne, Andy'" <andy.seaborne@hp.com>, "'Alan Ruttenberg'" <alanruttenberg@gmail.com>, <public-rdf-text@w3.org>, "'Sandro Hawke'" <sandro@w3.org>, "'Axel Polleres'" <axel.polleres@deri.org>
On May 20, 2009, at 11:32 AM, Boris Motik wrote:
> Hello,
>
> [snip]
>
>>> Furthermore, the addition of rdf:text to the mix of the supported
>>> datatypes adds
>>> no new conceptual problems to SPARQL: the situation with rdf:text is
>>> no
>>> different than with, say, xsd:integer (there are other examples as
>>> well). For
>>> example, assume that you have an RDF graph
>>>
>>> G = { <a, b, "1"^xsd:integer> }
>>>
>>> but you ask the query
>>>
>>> Q = { <a, b, "1.0"^^xsd:decimal> }.
>>>
>>> Clearly, G D-entails Q,
>>
>> Actually, not, according to XML Schema, which insists that primitive
>> datatype value spaces are disjoint. so the integer 1 is distinct from
>> the decimal 1.0. (I agree this can be counterintuitive, but for some
>> it is obviously correct.)
>>
>
> This is not true: xsd:integer is derived from xsd:decimal in XML
> Schema, so the
> value space of xsd:integer is a subset of the xsd:decimal. My
> example is
> correct.
>
Whoops, you are right. Sorry. Nevertheless, my main points still
stand. The key difference is that people are used to this issue (of
cross-domain identity) being one requiring care when dealing with
numerical formats, but not for pieces of plain text.
Pat
> [snip]
>
> Boris
>
>
>
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Received on Wednesday, 20 May 2009 17:26:15 UTC