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RDF Semantics and vocabularies and datatype entailments

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Wed, 09 May 2007 14:38:35 +0100
Message-ID: <4641CEDB.8050109@hpl.hp.com>
To: phayes@ihmc.us, semantic-web@w3.org, "Turner, David" <davidt@hp.com>


Hi Pat

my colleague David Turner has been going over OWL Semantics with a 
toothcomb, and asked me a question about datatype entailments that I can 
track back to questions about RDF semantics, and then I get stuck.

So, an example RDF test case is:

http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/test003a.nt
i.e.
eg:foo eg:bar "10"^^xsd:integer .

D-entails and is D-entailed by

http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/test003b.nt

eg:foo eg:bar "010"^^xsd:integer .

or, an OWL test case, such as
http://www.w3.org/TR/owl-test/byIssue#I5.8-004

which is a positive entailment, with
"5"^^xsd:byte
in the conclusions, but no such literal in the premises.

However, D-entailment is defined as:
http://www.w3.org/TR/rdf-mt/#D_entailment
[[
S D-entails E when every D-interpretation which satisfies every member 
of S also satisfies E.
]]

and then
D-interpretation at
http://www.w3.org/TR/rdf-mt/#defDinterp
requires the value space of the datatype to be a subset of LV, but does 
not require (as far as I can see) that the lexical space is part of the 
vocabulary.

This would suggest that the model theory and the tests are not in 
agreement. Since, according to the model theory there are 
D-interpretations of
eg:foo eg:bar "10"^^xsd:integer .
which do not contain "010"^^xsd:integer in the vocabulary, etc.

Have I misread something, or is this a bug?

Jeremy


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Received on Wednesday, 9 May 2007 13:39:28 UTC

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