Re: D7 - Which languages are better than OWL?
Dear Gian,
> "a representation using an n-ary relation can always be converted
> to a representation using a binary relation, without loss of
> semantics" ... "without loss of semantics" is false.
I was waiting/hoping for that feedback.
Unfortunately, I am missing the (fine) point(s) in both your
email and the article you cited:
1) Where is the loss of semantics when you translate
(giftOfSomethingBySomeoneToSomeoneSometime
book328 Mary128 Bill948 '12/9/2007')
into (I use the FCG notation here)
[a Gift, object: book328, agent: Mary128,
recipient: Bill948, date:12/9/2007]
or to [ [a Gift, object: book328, agent: Mary128,
recipient: Bill948], date: 12/9/2007]
I only see an increase of precision/semantic because
the roles have been explicited. As you acknowledge in
our article this decomposition avoids the combinatorial
explosion of relation types such as
giftOfSomethingBySomeoneToSomeoneSometime, which
furthermore cannot be ordered into a specialization
hierarchy (thus making knowledge re-use and comparison
difficult). I'd add the fact that you can quantify the
concept type 'Gift' (e.g., "2 Gift"or "any Gift") but not
the previous relation type. Hence, I think the primitive
notion here is the concept type Gift here, not the relation
types gift or giftOfSomethingBySomeoneToSomeoneSometime.
2) At the end of page 3 of your article, you hint at the
n-ary nature of the anonymously referred situation instance
(in my above example, the particular gift , say,
gift739ofSomeBookFromMary128ToBill948AtDate12/9/2007).
I personally see this instance as an instance of the
concept type Gift, not as an instance of an n-ary relationship
but, in any case, what are the consequences (where is the
loss of semantics)?
3) what are these inferences that must "NECESSARILY" be made in NKRL
even though NKRL can be fully translated from and to RDF?
(I actually only saw binary relations in the NKRL examples
of your article but I admit I have not yet read Section 3
in detail). Please use an example, preferably using KIF or FCG.
Given we are here departing a bit from the core goal of D7, it might
be better to answer to me directly and I'll then post a summary of
the underlying ideas in my structured format (when I understand
these ideas enough to give a good summary). I let you be judge.
Philippe