Re: RDF and Logic Programming (and Hypergraphs)

Harold,

If we can't meet in Berlin, we can do it here!
I read the paper and I have enjoyed it!
You know that I love declarative and mathematical languages (another DAML)
and from that perspective I wanted to raise my point about reification.
We see reification as a precise way to make associations between things.
(Dis)joint parts of a graph could be reified (to things) to associate
them with other things. It's a bit like (1 + 2) * 3 which is not the
same as 1 + (2 * 3) or 1 + 2 * 3 (which is ambiguous).
Also look to the power of a World Wide Web associative memory!
From an implementation point of view, reification is a reasonable thing.
To implement a statement we use an object with a reference to the subject
(statement), the predicate URI string, a reference to the object (statement)
and some other stuff to cope with variables and so on [1].
The serialization of these statements is maybe too lenghty in the current
reified RDF syntax. If we look to
Archive:  http://www.agfa.com/w3c/2000/euler23.066.zip
 Length  Method   Size  Ratio   Date    Time   CRC-32     Name
 ------  ------   ----  -----   ----    ----   ------     ----
   2333  Defl:X     408  83%  09-04-00  18:56  97444486   authen.axiom.rdf
    324  Defl:X     216  33%  09-06-00  19:03  5a84880e   authen.lemma.rdf
   1755  Defl:X     349  80%  09-06-00  19:37  29f49280   authen.proof.rdf
    738  Defl:X     269  64%  09-05-00  20:34  ed1f66db   extra.axiom.rdf
    518  Defl:X     244  53%  09-06-00  19:11  dd47401b   extra.lemma.rdf
   5043  Defl:X     546  89%  09-06-00  19:37  3e3183fb   extra.proof.rdf
   4734  Defl:X     401  92%  09-04-00  18:57  62b14ad5   graph.axiom.rdf
    298  Defl:X     199  33%  09-06-00  18:47  704b043f   graph.lemma.rdf
  22239  Defl:X     953  96%  09-06-00  19:37  94e7f9bd   graph.proof.rdf
   3957  Defl:X     378  90%  09-04-00  18:58  e10ceed1   lists.axiom.rdf
   1430  Defl:X     282  80%  09-06-00  18:57  a2270f4f   lists.lemma.rdf
  24042  Defl:X     702  97%  09-06-00  19:37  28dda6b5   lists.proof.rdf
 ------          ------  ---                              -------
  67411            4947  93%                              12
there is room for improvement (mean factor of 14 with a peak of 34).
I am at the end of my Latin today, but we are glad to learn more tomorrow.

Viele gruesse,
Jos De Roo --- AGFA

[1] http://www.agfa.com/w3c/euler/

Received on Tuesday, 12 September 2000 17:22:00 UTC