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Re: nonmon mapping and punning

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Wed, 23 Jan 2008 17:44:37 +0000
Message-ID: <47977D05.1050906@hpl.hp.com>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
CC: public-owl-wg@w3.org

Peter F. Patel-Schneider wrote:

> When would a triple-based implementation have to modify "a triple in
> response to adding a triple"?  Which design principle does this violate,
> and where did it come from?
> 


If I have understood correctly, the following sequence of operations, at 
an API level, would result in this situation. I'll express it as a merge 
of two ontologies, in order to answer your second question about design 
principle.


A program manipulates an API, such as the Jena Ontology API

http://jena.sourceforge.net/ontology/index.html

It creates an ontology and adds an object property p to it, and adds a 
maxCardinality restriction on p. This ontology is then written out to a 
file.

If I understand correctly the RDF/XML corresponding to the 
maxCardinality restriction should have type owl:Restriction

It then creates a second ontology and adds a data property, also called 
p to it, and adds a minCardinality restriction on p. This second 
ontology is then written out to a second file.

If I understand correctly the RDF/XML corresponding to the 
minCardinality restriction should have type owl:Restriction

It then creates a third ontology, being the union of the first two, 
corresponding to the RDF merge operation.

If this is written out to a third file, in a way that conforms with OWL 
1.1 DL, then

If I understand correctly the RDF/XML corresponding to the 
maxCardinality restriction should have type owl:ObjectRestriction

and
the minCardinality restriction should have type owl:DataRestriction.


This has involved the deletion of two triples with predicate rdf:type 
and object owl:Restriction.

Our expectations for merge are found in RDF Semantics, for example,

http://www.w3.org/TR/rdf-mt/#mergelem
[[
Merging lemma. The merge of a set S of RDF graphs is entailed by S, and 
entails every member of S.

This means that a set of graphs can be treated as equivalent to its merge
]]

Jeremy
Received on Wednesday, 23 January 2008 17:45:02 GMT

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