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Re: assymetric reference of properties

From: Eric Hellman <eric@openly.com>
Date: Thu, 27 Jan 2000 22:46:16 -0500
Message-Id: <v04220807b4b6bfab56b3@[192.168.1.1]>
To: martin <martin@csi.forth.gr>, www-rdf-interest@w3.org
We encountered the same situation in our linking metadata schema. A 
lot of code was expended making sure that we don't get stuck in 
endless loops while traversing models with these reciprocal 
relationships- probably its a good excuse to keep the "inverse" 
property out of rdfs. But I certainly agree that it's a needed 
facility at some level.

Eric

At 11:48 AM +0200 1/26/00, martin wrote:
>Dear collegues,

<stuff deleted>

>In the CRM we have foreseen an "inverse name" for all data models, which
>do have the above problem. I.e. as convenient, users may either use
>the name "is identified by" for the property in the first example,
>or the name "identifies" for the its inverse. The simultaneous provision
>of both links as above, without further formal semantics, seems not
>to be very satisfactory.
>
>I can imagine 3 solutions:
>
>a) A statement is introduced in RDFS, stating that property B is the
>    inverse of property A. This would allow at least to formally exchange
>    information about the inverse equivalence of A and B.
>b) RDF descriptions are extended to declare property instances of the
>    inverse of a property type. This would avoid double declaration,
>    lead to redundance-free models, but make an arbitrary decision to
>    from where the "original" property is read. The use of the inverse
>    property type becomes less comprehensive to read for humans.
>c) RDFS is extended to register two names for each property, a forward
>    and a backward one, as we propose in the CRM, and RDF descriptions
>    allow for either use according to the direction of use. The latter
>    seems to us the most appropriate solution.
>
>Comments welcome.
>
>Martin Doerr

Eric Hellman
Openly Informatics, Inc.
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Received on Thursday, 27 January 2000 22:46:29 GMT

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