W3C home > Mailing lists > Public > www-rdf-logic@w3.org > June 2001

RE: rdf as a base for other languages

From: Jonathan Borden <jborden@mediaone.net>
Date: Mon, 4 Jun 2001 23:11:28 -0400
To: "Wolfram Conen" <conen@gmx.de>
Cc: <www-rdf-logic@w3.org>
Message-ID: <002601c0ed6d$3690eea0$0201a8c0@ne.mediaone.net>
Wolfram Conen wrote:
>
> Jonathan Borden (J), Wolfram Conen (W) wrote:
> J: Hence what should be a simple construct:
> J:  (not (color sky blue))
> J: becomes contorted.
>
> W: Yes, if you model this as (for example):
> W: [sky color blue]
> W: [r type statement][r subject sky][r predicate color][r object blue]
> W: [r hasTruthvalue not]
> W: it becomes a little bit diffult* (see additional remark below, if you
> W: like).
>
> J: Not just "difficult", I would say this is a logical contradiction.
>
> Before we could talk about contradictions, we would have to agree on
> semantics (of RDF/set of triples). It is not a contradiction "per se".

Certainly. my issue here is that RDF M&S 1.0 _defines_ a statement/triple as
a fact.
remove this _definition_ and the need for the RDF reification contortion
goes away. So RDF reification is really a bad solution to a problem the
specification has created. hmmmm how to fix this?

>
> You may not consider this to be a perfect way of giving some meaning to
> (a part of) RDF, but it seems not to be completely unreasonable (I hope)
> - and the triples are not a contradiction any more. (this is to say that
> before we have agreed on semantic interpretation, we probably shouldn't
> say that a set of triples is contradictory).

I agree. However, the spec _does_ appear to dabble in semantic
interpretation.

>
> Once you start to "interpret" triples with a host formalism, you may
> easily get rid of reification if you interpret it as nesting. That is:
> the 2nd version from above can be written as [[sky color blue]
> hasTruthValue FALSE].

yes!

>
> Do you mean that you can not encode this without asserting not(s) with
> the suggested method (you can, as long as you do not make the first [r
> hasTruthValue FALSE] explicit - that is: keep on reifying ... ;)?

or not reify at all... as you suggest above. at some level reification
appears to me as if I were required to quote other english speaking people
in swahili in order to distinguish what they and I are saying. yet what if
they are quoting something in english ... or perhaps if they quote german we
can agree to represent it in french ... well there's really no end to the
confusion that one can construct :-))

>
> J: regardless this seems contorted at best.
>
> Yes, sure, but all we have are triples and so we have to make something
> useful out of it - and can't this be done, for exmaple, with "formal"
> mappings of RDF triples into constructs of a host formalism? wouldn't it
> be nice if some such mappings would be availaible (usable like a
> toolbox) and each one could pick out what he needs, make this explicit
> and start to interoperate happily?

Yes, well it can be done as n-tuples can be represented as triples. Just as
my now 21 month old daughter speaks reasonably adeptly in 3 word sentences,
I choose to use more complex structures on occasion. Of course whatever we
do does require a change to what RDF we have now (i.e. 1.0). I suggest that
we discuss what is _best_ not what is merely possible. And realize that as
256 Mb memory sticks have become quite cheap we don't need to be as stingy
with tuple arity as 2 years ago. Remember that the Semantic Web has lofty
goals and we ought not send it out in the jungle with dull knives :-)

-Jonathan
Received on Monday, 4 June 2001 23:13:00 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:52:40 GMT