W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2003

Re: substantive semantics change?

From: pat hayes <phayes@ihmc.us>
Date: Wed, 12 Nov 2003 11:06:05 -0600
Message-Id: <p06001f07bbd818edddb6@[10.1.31.1]>
To: "Jos De_Roo" <jos.deroo@agfa.com>
Cc: w3c-rdfcore-wg@w3.org

>Jeremy:
>[...]
>>  I don't follow the transitivity argument ...
>>
>>  G entails H if every interpretation of G is an interpretation of H.
>>
>>  this is clearly transitive, and a "counter-example" like
>>
>>  *empty*
>>    entails
>>  rdf:_1 rdf:type rdfs:Resource
>>    entails
>>  rdf:_1 rdf:type rdfs:ContainerMembershipProperty
>>
>>  is flawed because the first entailment is false according to the LC2
>>  semantics.
>
>In the LC2 semantics I read
>
>[[
>Even the empty graph has a large number of rdfs-entailments which
>are not rdf-entailments, for example all triples of the form
>
>xxx rdf:type rdfs:Resource .
>
>are true in all rdfs-interpretations of any vocabulary containing xxx.
>]]
>
>so this is about the *empty* premise graph and
>
>[[
>A set of names is referred to as a vocabulary. The vocabulary
>of a graph is the set of names which occur as the subject,
>predicate or object of any triple in the graph. Note that
>URI references which occur inside typed literals are not
>required to be in the vocabulary of the graph.
>]]
>
>so I guess xxx is in the vocabulary of the conclusion graph
>and so I don't see where the above entailment is flawed...
>

Yes, quite.

Pat

>--
>Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/


-- 
---------------------------------------------------------------------
IHMC	(850)434 8903 or (650)494 3973   home
40 South Alcaniz St.	(850)202 4416   office
Pensacola			(850)202 4440   fax
FL 32501			(850)291 0667    cell
phayes@ihmc.us       http://www.ihmc.us/users/phayes
Received on Wednesday, 12 November 2003 12:06:06 EST

This archive was generated by hypermail pre-2.1.9 : Wednesday, 12 November 2003 12:06:08 EST