Re: How do RDF and Formal Logic fit together?

[RA Poell]

> [Thomas B. Passin]
> >
> > To hook this into the threads on literals, how is your DatExpert
supposed to
> > know that a given string is to be analyzed as a date, if we cannot make
a
> > statement about the type of the literal?  The only other ways would seem
to
> > be textual (or contextual) analysis which are pretty hard, or human
> > intervention which is fine but not so Semantic Webish.
> >
>
> The name of a slot or property ("Birth date") should give you an
> indication that a date is involved (semantics for human use and machine
> exploitation if we tell them to use this in particular cases).
>
> The type of property value ("date") tells you it should be looked upon
> as a date (semantics for machine exploitation).
>
> But the format, at least in my broader perception of dates, will always
> be a string in its physical representation.
>
> The way the string should be interpreted (logical format?) making it
> machine understandable in terms of a date can be added if known (Format:
> string = referring to a node | yyyy-mm-dd | DatExpert:absoluteValue |
> .).

So basically, your approach would supply tyoe information either by adorning
the literal value or by using special properties, is that right?  To me,
this amounts to adding a datatyping system to RDF, one of a number of
candidates.  Restricting the "slot" - or property, I suppose - to require
certain data types like dates means applying constraints to a template, but
RDF does not have native templates.

I don't mean to suggest your approach does not have merit, but I take it
that the bigger questions of whether RDF should have a datatyping system at
all, and whether literal should be able to be targets of statements (or
alternatively be allowed at all) seem to more the subject of these threads.

Cheers,

Tom P

Received on Sunday, 7 October 2001 11:16:16 UTC