On Jul 7, 2010, at 6:57 AM, Toby Inkster wrote:
On Tue, 6 Jul 2010 16:11:19 -0500
Pat Hayes <[email protected]> wrote:
The world doesn't have facts like that in it. Classes and properties
are intellectual constructs, not the stuff of reality. Hell, if a
particle can be a wave, then surely a class can be a property.
Anyway, RDF doesn't make logical a priori rulings about these kind
of metaphysical segregations. For example, xsd:Number is a class, a
property and an individual in RDF.
Indeed - but who has claimed that classes and properties are disjoint?
Although they may well overlap in some cases, foaf:Person still
isn't a
property.
Without knowing the definition of foaf:Person, it's difficult to
conclude that foaf:Person is not a property. However, even without
knowing the definition of a literal, it is easy to conclude that it is
not a suitable node to be used as a property
Well, thats what I thought too, until people started using them that
way in CLIF/IKL. It is very dangerous to presume that one can see
clearly, ahead of time, that a construct cannot be usefully be used by
anybody else. And such triples do have a meaning, technically, since
the RDF semantics gives them one, without indeed any modification *at
all*.
, so in my opinion, it is
sensible to state that triples containing a literal as the predicate
have no meaning (even though I think they should be syntactically
allowed).
I would veto this option. To do this would be a lot more work than not
doing it; and it would greatly complicate the semantic specification,
which would have to keep track of this 'meaninglessness'. One could
have a situation, for example, in which A entails B entails C, A and C
are perfectly fine, but B has been declared 'meaningless'. Should this
inference be blocked? Should it be an error? Why are we even asking
this question?
Pat
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Toby A Inkster
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