Re: true/false in RDF?

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://xmlns.com/wordnet/1.6/true
http://foobar/page.html  urn:myterms:isCached  
http://xmlns.com/wordnet/1.6/false
http://foobar/page.html  urn:myterms:isCached  
http://xmlns.com/wordnet/1.6/Salad
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
baggage.

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

Hmm, maybe not as viral as:

struct Page
{
    public boolean IsCached;
...
}

Cheers,
Danny.







-- 

http://dannyayers.com