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Re: incompleteness in RDFS closure rules

From: pat hayes <phayes@ihmc.us>
Date: Mon, 9 Jun 2003 13:39:52 -0500
Message-Id: <p05210612bb0a7993da2a@[10.0.100.24]>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: www-rdf-comments@w3.org, Jos De_Roo <jos.deroo.jd@belgium.agfa.com>, Graham Klyne <gk@ninebynine.org>

>	rdfs:subClassOf rdfs:subPropertyOf xxx .
>	xxx rdfs:domain yyy .
>
>RDFS-entails
>
>	rdfs:Class rdfs:subClassOf yyy .
>
>but this does not come out of the RDFS closure rules.
>
>
>
>	rdfs:subClassOf rdfs:subPropertyOf xxx .
>	xxx rdfs:range yyy .
>
>RDFS-entails
>
>	rdfs:Class rdfs:subClassOf yyy .
>
>but this does not come out of the RDFS closure rules.
>
>
>
>	rdfs:subPropertyOf rdfs:subPropertyOf xxx .
>	xxx rdfs:domain yyy .
>
>RDFS-entails
>
>	rdf:Property rdfs:subClassOf yyy .
>
>but this does not come out of the RDFS closure rules.
>
>
>
>	rdfs:subPropertyOf rdfs:subPropertyOf xxx .
>	xxx rdfs:range yyy .
>
>RDFS-entails
>
>	rdf:Property rdfs:subClassOf yyy .
>
>but this does not come out of the RDFS closure rules.


Yes, you are perfectly correct. The rule rdfs12 has been generalized 
to include these cases, as follows:

rdfs12a

ppp rdfs:subPropertyOf zzz .
ppp rdfs:domain xxx .
zzz rdfs:domain yyy .
|-
xxx rdfs:subClassOf yyy .

rdfs12b

ppp rdfs:subPropertyOf zzz .
ppp rdfs:range xxx .
zzz rdfs:range yyy .
|-
xxx rdfs:subClassOf yyy .

where in 12a, ppp is one of rdf:type, rdfs:subPropertyOf, 
rdfs:subClassOf, and in 12b only the last two are allowed (because an 
empty class need not be in the range of a superproperty of rdf:type). 
Including rdf:type in the 12a case covers the inference noticed 
earlier by Herman, though the rationale is somewhat different.  These 
rules are not valid more generally because of the inclusive nature of 
domain and range.

BTW, the URI of the current editors draft has changed somewhat: these 
changes are now visible at

http://www.ihmc.us/users/phayes/RDF_Semantics_Edit_nT.html

Thanks for noticing this.

Pat

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Received on Monday, 9 June 2003 14:39:55 GMT

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