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Re: true/false in RDF?

From: Danny Ayers <danny.ayers@gmail.com>
Date: Thu, 17 Mar 2005 01:33:28 +0100
Message-ID: <1f2ed5cd05031616336da1931@mail.gmail.com>
To: Joshua Allen <joshuaa@microsoft.com>
Cc: rich@boakes.org, Seth Russell <russell.seth@gmail.com>, semantic-web@w3.org

On Wed, 16 Mar 2005 15:12:13 -0800, Joshua Allen <joshuaa@microsoft.com> wrote:

I must confess I've not grokked the benefits of Rich's indirection yet, but...

> This whole strong-typed concept is mystifying me; it seems people cannot
> restrain themselves from injecting Java class hierarchy concepts into
> everything even when they do not need it or use it (the same problem
> with XSD, BTW).  

I don't think the modelling in this thread has been about injecting
anything, quite the opposite - it's using what's available in the
language. There aren't variables, the open world assumption means it's
not easy to be negative, the obvious constructs for true/false just
don't work. The following statements are entirely consistent with each
other, all asserted at the same time:

http://foobar/page.html  urn:myterms:isCached  
http://foobar/page.html  urn:myterms:isCached  
http://foobar/page.html  urn:myterms:isCached  
http://foobar/page.html  urn:myterms:isCached   http://xmlns.com/foaf/0.1/Person

Most of RDF's (RDFS's) reasoning capability comes through
relationships between classes/properties, which are quite a distance
removed from the class hierarchies of Java. The individuals
individuals are just named things, not objects carrying loads of

Class hierarchy seems like a mental virus that takes
> over our brains.

Hmm, maybe not as viral as:

struct Page
    public boolean IsCached;



Received on Thursday, 17 March 2005 01:39:44 UTC

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