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Re: Questions About DAML+OIL Restrictions

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 18 Apr 2001 07:32:45 -0400
To: fikes@KSL.Stanford.EDU
Cc: www-rdf-logic@w3.org
Message-Id: <20010418073245H.pfps@research.bell-labs.com>
From: Richard Fikes <fikes@KSL.Stanford.EDU>
Subject: Questions About DAML+OIL Restrictions
Date: Tue, 17 Apr 2001 22:04:14 -0700

> Here are some other questions about the DAML+OIL language spec on which
> I would like clarification:
> 
> Can a restriction have more than one value for property "onProperty?  If
> not, is that constraint stated anywhere in the spec?

There is, indeed, no limit here.

> Can a restriction have values for more than one of the properties
> "toClass", "hasClass", "hasValue", "hasClassQ", "minCardinality", ...,
> "minCardinalityQ"?  That is, can a single restriction state multiple
> constraints?

Again, no limit.

> Is it the case that the following restriction:
> 
> (type R Restriction)
> (onProperty R P)
> (hasClass R C)
> 
> is logically equivalent to the following restriction:
> 
> (type R1 Restriction)
> (onProperty R1 P)
> (hasClassQ R1 C)
> (minCardinalityQ R1 1)
> 
> If so, what is the rationale for having "hasClass" in the language?

These two are equivalent.  hasClass is present at least partly to be an
analogue to toClass.

Note that there are lots of redundant constructors in DAML+OIL.  (Think of
complementOf.)


> Richard

peter
Received on Wednesday, 18 April 2001 07:34:07 GMT

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