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Re: Strawman Model Theory

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Mon, 23 Jul 2001 19:41:44 +0100
Message-ID: <3B5C6FE8.72305ED2@hplb.hpl.hp.com>
To: jos.deroo.jd@belgium.agfa.com
CC: w3c-rdfcore-wg@w3.org


jos.deroo.jd@belgium.agfa.com wrote:
> 
> Nice work, really!
> 
> [...]
> 
> > Let U be the set of URI References (as defined by RDF 2396).
>                                                     ^^^RFC

Yup - its like my car knowing the way to work - when I hit that
capital R the D and F surely follow :)

> >
> >                           //ignore lang and namespaces for now
> > Let S be the set of of UNICODE strings (UNICODE*)
> 
> I guess U and S are denumerable, no?

Yes

> 
> > An interpretation I consists of:
> >
> > A set R of thingies
> >
> > A subset P of thingies which corresponds to Properties
> >
> > A mapping IN : U -> R
> >
> > A mapping IEXT : P -> R x R            // R cross R
> 
> Isn't the notation f: A -> B used for a function with
> domain A and range B?

Yes

> But IEXT is not a funtion at all, it is a relation on
> a cross product R x R which is simply a subset of R x R
> IEXT(I(p)) = {<I(s),I(o)> el R x R: I(s) I(p) I(o) is true}

Yes there's something screwy about what I wrote.  I think I
meant to write:

IEXT : P -> powerset(R x R)

i.e. IEXT is a mapping from from P to relations on R - the
idea being to ensure that R x R is not a subset of R.

Is that the same as you are suggesting?

Brian
Received on Monday, 23 July 2001 14:44:21 EDT

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