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Re: need to determine what RDF is

From: patrick hayes <phayes@ai.uwf.edu>
Date: Thu, 30 May 2002 12:12:54 -0500
Message-Id: <p05111700b91c065d3146@[]>
To: "Seth Russell" <seth@robustai.net>
Cc: <www-rdf-comments@w3.org>

>From: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
>>  Suppose an agent is given
>>    <ex:Student> <rdfs:subClassOf> <ex:Person> .
>>    <ex:John> <rdf:type> <ex:Student> .
>>    <rdfs:subClassOf> <rdf:type> <rdf:Property> .
>>    <rdfs:subClassOf> <rdfs:domain> <rdfs:Class> .
>>    <rdfs:subClassOf> <rdfs:range> <rdfs:Class> .
>>    <rdfs:Class> <rdf:type> <rdfs:Class> .
>>  and responds that it entails
>>    <ex:John> <rdf:type> <ex:Person> .
>>  This agent is not an RDF reasoner (is not doing RDF).  Its reasoning is
>>  unsound in RDF.  The agent may be an RDFS reasoner, but it is not doing
>>  RDF.
>I agree, given *only* the assertions in the rdf namespace, there is no way
>that an automated agent *could* arrive at that entailment.  But given the
>logical interpretation of certain rdfs:comments,

WHAT logical interpretation of comments? Those comments are written 
in English, not in any formal logic. So until someone comes up with a 
model theory for English (and incorporates it into a Web language 
spec) they have no logical interpretation. (Isn't this obvious? 
That's why we call them 'comments'. If they were comments in a piece 
of Java code, nobody would expect the Java VM to be able to read them 
and take their meaning into account.)  Bear in mind that this entire 
SW game is supposed to be putting stuff on web pages that can be used 
by software reasoning agents, not by human readers.

>  it certainly can be
>entailed.   I seems to me that any automated agent that attempts to arrive
>at conclusions about assertions, without knowing any rules that apply to its
>predicate, would always be going beyond the data given.

No, that is precisely what it cannot do. The *automated* agent only 
knows the 'rules' that are specified by the formal part of the 
language spec and the formal language it can read. Comments are 
invisible to it. It *cannot* go beyond the data given.

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Received on Thursday, 30 May 2002 13:12:48 UTC

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