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Re: A test case? [Re: Before we go on...]

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Fri, 19 Apr 2002 20:31:34 -0500
Message-Id: <p05101501b8e6711559bc@[65.217.30.94]>
To: Patrick Stickler <patrick.stickler@nokia.com>
Cc: w3c-rdfcore-wg@w3.org
>On 2002-04-19 13:23, "ext Brian McBride" <bwm@hplb.hpl.hp.com> wrote:
>
>>  ...  Is there an entailment test here?
>
>Here's mine.
>
>Given the following closure rules:
>
>.....
>
># Rule 4 (this is new)
>
>{
>    ?p rdfd:datatype ?d .
>    ?s ?p ?l .
>    ?l rdf:type rdfs:Literal
>}
>log:implies
>{
>    ?s ?p ?o.
>    ?o rdfd:lex ?l
>} .

I don't think rule 4 is valid. That is, Im not sure quite what
?l rdf:type rdfs:Literal .
is intended to convey, but if its supposed to say that the object of 
the previous triple is a literal, then the rule is not valid. Here's 
a counterexample:

Suppose IEXT(I(<ex:PPP>)) is the identity map. Then for example I satisfies

_:x <ex:PPP> "10" .
<ex:PPP> rdfd:datatype <xsd:integer> .

(map _:x to "10"; all literal strings are in the universe; "10" is in 
the lexical space of the datatype) but not

_:x <ex:PPP> "10" .
<ex:PPP> rdfd:datatype <xsd:integer> .
_:x <ex:PPP> _:y .
_:y rdfd:lex "10" .

since this requires _:y to denote an integer, and so requires 10 to 
equal "10" in that datatyped interpretation.

Pat


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Received on Friday, 19 April 2002 21:31:41 EDT

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