Re: [BLD] some more commments which I didn't manage to type in yesterday...

Axel Polleres wrote:
> attached some comments for Sec 4, which I didn't manage to type in 
> yesterday.
> 

sorry, one of the attachments was the wrong file :-)
attached again!

axel


-- 
Dr. Axel Polleres
email: axel@polleres.net  url: http://www.polleres.net/

Non-editorial comments, clarifying questions and issues:

2nd part, those comments which I didn't manage to type in yesterday.

These comments are based on
http://www.w3.org/2005/rules/wg/bld/draft-2007-09-24.html
and might be subsumed by others comments already, apologies if so.

Starting off from Section 4

1)
"*** The working group will have to decide whether to specify compatibility with both OWL DL and Full, or with just one of the two. [...]"

Why? another option is differenct dialects for different OWL dialects.


2) 

"For example, direct rule-based processing can be done by suitably restricting the OWL component to a so-called DLP subset."

to be fair, we should state as well:

"or restricting the rules part to e.g. DL-safe rule"
However, we should check here whether and how we interfer with the new OWL WG charter, since they were talking about such extensions.

3)
"a) There are no requirements on the shape of the OWL DL ontology. b) RIF recommends to use only the DLP subset of OWL DL in combination with RIF; anyone wanting to go beyond this subset is on their own wrt. processing. c) RIF only defines the combination for the DLP subset of OWL DL."

Again, an alternative would be to do own dialects for these options.

4) Question on D-Entailment? Is that that simple-, RDF- and RDFS-entailment are parametrized with D, or D-entailment is a single separate entailment regime?

5) 
"whereas RIF has a fixed number of datatypes, so it essentially has a fixed datatype map. Combinations of RIF with RDF under D-entailment are only defined for the case where D corresponds to the fixed datatype map of RIF."

I suggest to replace "fixed" by "dialect fixed datatype map" And note that the BLD
datatype map can be extended by dialects but that "D^<dialect>" mapes need to 
be defined by each dialect.

This maybe raises an issue for extensibility how the Datamaps are defined for a dialect...
but well, there isn't much defined in terms of extensibility anyway so far.

6) 
"
A typed literal (s, u) is a well-typed literal if
   1. u is in the domain of DRIF and s is in the lexical space of DRIF(u)
   2. u is the URI of a symbol space defined by RIF and s is in the lexical space of the symbol space, or
   3. u is not in the domain of DRIF and is not a symbol space defined by RIF.
"

what is the diff betwen 1. and 2., don't they subsume each other?


7) 
"
VU* is obtained from VU by replacing every RDF URI reference URI in VU 
with "URI"^^rif:iri.
"

How would we treat RDF typed literals... being typed by "rif:iri" (or "rif:text") then
wouldn't that be ambiguous?

8) Is the @@ encoding within rif:text not superfluous? The last @ always 
identifies the separation. A cleaner/simpler solution would be:

Define for each lang tag an XML simple type as a subtype of rif:text
e.g
rif:text@en
rif:text@de
...
and use those types