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Re: Input sought on datatyping tradeoff

From: Jonathan Borden <jonathan@openhealth.org>
Date: Fri, 12 Jul 2002 12:25:08 -0400
Message-ID: <001901c229c1$24001f90$0201a8c0@ne.mediaone.net>
To: <www-rdf-logic@w3.org>, "Brian McBride" <bwm@hplb.hpl.hp.com>
Cc: <www-rdf-comments@w3.org>, "patrick hayes" <phayes@ai.uwf.edu>

Brian McBride wrote:
>
> At 09:35 12/07/2002 -0400, Jonathan Borden wrote:
> >Brian McBride wrote:
> >
> >
> > >
> > > Because the A tests have no range constraint.  We either have to
decide
> > > that literals are self denoting - they always denote themselves in
which
> > > case the answer to D must be NO, or there denotation depends on a
range
> > > constraint in which case the answer to A must be NO.
> >
> >I don't follow. Assuming literals always denote themselves (which is the
> >"duh!" test I was refering to), why MUST D be NO?
>
> Because a string and an integer are never equal.

I'm sorry -- I've not seen an actual integer in this discussion, certainly
not in the N-triples nor RDF/XML that you've written.

The point is that we _are actually_ talking about literal strings that might
be _interpreted as_ integers -- but the object of the triple is either a
URIref or literal string. So "10" === "10".

Of course I agree that integerValueOf("10") = 10, but this isn't part of RDF
e.g. you can't say:

<Mary> <age> 10 .

So ultimately all integers are _interpreted_ as integers by the RDF model
theory (i presume) or ultimately some piece of software that knows how to
convert a string into an integer.

>
>
> >That is to say, a _literal_ is defined as something _without_ an
rdfs:range,
> >and a _value_ is something _with_ an rdfs:range, so why can't each have
> >their own "eq" rules?
>
> I agree with you here that
>
>    integerValueOf("10") = 10
>
> but that doesn't make "10" = 10.

correct. This is my point:

"10" = "10" (duh!)

and you _can interpret_

integerValueOf("10") = 10

is there a problem?
>
> [...]
>
> >Perhaps I am being dense so help me, suppose I have a set of triples
> >_without_ an rdfs:range and I say "not equal" and then I add a triple
with
> >an rdfs:range, and then I say "equal" how isn't that non-monotonic?
Aren't
> >_both_ "equal" and "not equal" inferences in this specific case?
>
> Concluding "not equal" is not the same thing as not concluding "equal".
It
> is possible to not know enough to conclude one way or the other.  But I
> should leave this conversation the logicians.
>

The point is that: not knowing enough _is different_ from concluding either
"equal" or "not equal" (and your question was about "equal" vs. "not equal"
unless I am misinterpreting the meaning of "NO" in previous messages).

In any case if you are going to try and say that "10" <> "10" then you fail
the duh! test and that is a nonstarter as far as I am concerned -- there are
enough folks who already think RDF is weird, and such a decision would case
a _field day_ of howls. What I am trying to say is that I don't think the
'common man on the street' would accept that.

On the other hand that doesn't prevent one from infering that:

integerValueOf("10") = 10

which is the purpose of a formalism, no?

Jonathan

Jonathan
Received on Friday, 12 July 2002 12:44:25 GMT

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