Re: entailments and the unstar mapping

Enrico, Pierre-Antoine,


Le 20/03/2023 à 23:21, Franconi Enrico a écrit :
> 
[...]
> 
> Observe the following (with semantic predication):
> <<:a :b :c>> owl:sameas <<:d :e :f>> .
> entails (and it is entailed by)
> :a owl:sameas :d .
> :b owl:sameas :e .
> :c owl:sameas :f .
> but this can not be captured with the L/unstar transformation under RDF 
> 1.1 simple entailment augmented with owl:sameas.

No, this is not the case in the semantics of the CG report.

Let us assume that this prefix is set:
@prefix : <http://ex.net/> .

Then:

unstar(<<:a :b :c>> owl:sameAs <<:d :e :f>>) =

{
   [] unstar:subject :a;
      unstar:predicate :b;
      unstar:object :c;
      unstar:subject "http://ex.net/a";
      unstar:predicate "http://ex.net/b";
      unstar:object "http://ex.net/c";
      owl:sameAs [
         unstar:subject :d;
         unstar:predicate :e;
         unstar:object :f;
         unstar:subject "http://ex.net/d";
         unstar:predicate "http://ex.net/e";
         unstar:object "http://ex.net/f"
      ] .
}

on the other hand:

unstar(:a owl:sameas :d . :b owl:sameAs :e . :c owl:sameAs :f .) =

{
   :a owl:sameAs :d .
   :b owl:sameAs :e .
   :c owl:sameAs :f .
}

This does not follow from that.


Perhaps what you meant was "the semantics based on unstar mapping does 
not provide the intuitive entailment that we want whenever we add at 
least ow:sameAs". Which is a very different statement. In fact, I do not 
accept that this entailment follows intuition. It depends what is meant 
by an embedded triple.

Suppose we have:

<<:john :identicalTwinOf :jack>>
     owl:sameAs <<:jack :identicalTwinOf :john>> .

This may mean that the triple ":john :identicalTwinOf :jack" is the same 
as the triple ":jack :identicalTwinOf :john" (which is obviously 
inconsistent), or that :jack is the same as :john, or that the two 
embedded triples express the same truth.

--AZ

> 
> cheers
> —e.
> 

-- 
Antoine Zimmermann
École des Mines de Saint-Étienne
158 cours Fauriel
CS 62362
42023 Saint-Étienne Cedex 2
France
Tél:+33(0)4 77 49 97 02
http://www.emse.fr/~zimmermann/

Received on Thursday, 23 March 2023 16:15:18 UTC