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ISSUE-18 (property typing): REPORTED: Fine-grained property typing

From: OWL <sysbot+tracker@w3.org>
Date: Wed, 24 Oct 2007 21:16:42 +0000 (GMT)
To: public-owl-wg@w3.org
Message-Id: <20071024211642.3D6F3C6DB0@barney.w3.org>

ISSUE-18 (property typing): REPORTED: Fine-grained property typing


Raised by: Peter Patel-Schneider
On product: 

Reported by jlc415, Jun 11, 2007

In OWL-DL whether a role name represented an object or a datatype property was inferred 
globally on the basis of the entire ontology. (If it was not possible to infer which type a property 
was, then the difference did not make any difference to interpretation of the ontology.) It was 
possible to use a property in (for example) cardinality restrictions without making it explicit 
which type of property was used.

The current syntax specification requires that every use of a property explicitly encode whether 
the property should be treated as a datatype or as an object property. The extra verbosity 
required might not be considered an issue for the (already cumbersome) abstract syntax, but it 
prevents any terse alternate syntax from being converted to a valid OWL 1.1 fragment. 
Manchester OWL Syntax, for example, lets one to write expressions along the lines of

hasAddress atleast 1

but there are two possible translations of this expression to OWL 1.1:

ObjectMinCardinality(1 hasAddress)


DataMinCardinality(1 hasAddress)

This is a significant problem for interfaces which allow users to write OWL fragments in isolation.

This issue is related to that of object/datatype property punning. If such punning were 
disallowed then there would be no need for such explicit typing.
Received on Wednesday, 24 October 2007 21:16:56 UTC

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