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Re: Madonna

From: Henry Story <henry.story@bblfish.net>
Date: Wed, 9 Feb 2005 21:24:32 +0100
Message-Id: <53a47fa5f7efe4f1a36b767bdae9bc8f@bblfish.net>
Cc: "Jeremy Wong" <50263336@student.cityu.edu.hk>, <semantic-web@w3.org>
To: "Joshua Allen" <joshuaa@microsoft.com>

On 9 Feb 2005, at 19:45, Joshua Allen wrote:
>> [[
>>   It assumes, implicitly, that URI references have the  same meaning
>> whenever they occur. To provide an adequate  semantics which would be
>> sensitive to temporal changes is a  research problem which is beyond
>> the scope of this document.
>> ]]
>>
>> That is really no problem. It is exactly what first order logic does.
>
> I assume they are referring to any of the many philosophical
> "challenges" regarding identity which led people to assert that FOL was
> broken and invent new systems.  The literature is replete with fun
> little scenarios that can confuse FOL (or any other system for that
> matter).
>
> On the other hand, I agree that the semantics of FOL (and RDF) are
> completely adequate for many useful cases, and we can make considerable
> progress using the simple semantics and simple scenarios without having
> to solve the age-old philosophical problems.

Yes. For example it is very easy to express properties about temporal
objects.

:M1 --is-a-----> <3DPerson>
  |---ssn-------> <urn:ss:123456789>
  |---name------> "Madonna"
  |---size------> 170cm
  |---sex-------> <female>
  |---age-------> "16 years"

:M2 --is-a-----> <3DPerson>
  |---ssn-------> <urn:ss:123456789>
  |---name------> "Madonna"
  |---size------> 170cm
  |---sex-------> <female>
  |---age-------> "20 years"

given that ssn is a functional property from a <3DPerson> to a social
security urn, we have no problem. A 3DPerson is a Person in space. Ie
it is you now, or me now. But not me from my birth to my death, or the
even larger me that is the set of all my 4D possible world counterparts.

If we now wish to speak of a 4 Dimensional, spatio temporal person,
the thing that the Social Security Number really identifies, the
unchanging thing it identifies, the me from my birth to death,
then we have

:MM --is-a------> <4DPerson>
  |------ssn-----> <urn:ss:123456789>
  |----sex-------> <female>

when ssn relates a 4DPerson to a social security urn
then it is also inverse functional.

we then need a mereology vocabulary to say something like

:MM
  |----hasPart---> :M1
  |----hasPart---> :M2
  ...

Henry Story
Received on Wednesday, 9 February 2005 20:24:59 UTC

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