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RE: My answers to Jie Bao's review of the Full Semantics

From: Michael Schneider <schneid@fzi.de>
Date: Wed, 17 Sep 2008 14:42:21 +0200
Message-ID: <0EF30CAA69519C4CB91D01481AEA06A0B98E58@judith.fzi.de>
To: "Jie Bao" <baojie@cs.rpi.edu>
Cc: <public-owl-wg@w3.org>
Hi Jie!

Jie Bao answered to me:

>>    Introduction:
>>    """
>>    In the RDF Semantic documents, there are some nice diagrams
>>    to visualize interpretations. It may be better to have similar
>>    diagrams in this document.
>>    """
>>
>> I do not intend to add such figures. Being only examples, they are
>purely informative, and thus would rather be something to put in the
>Primer, not in the technical spec. Remember that we had a general
>discussion at F2F2 on not having too many examples in the technical
>documents.
>>
>What in my mind is that some pictorial representation of the relations
>between basic sets. I attached one I used in a seminar talk. Please
>forgive its ugliness and over-simplification. My suggestion is meant
>to add something like this.

I think, having a single picture visualizing the parts hierarchy and the IEXT/ICEXT-concept is perhaps a useful addition to the current text in the intro. I have added an Editor's note citing your comment as a place holder for the moment:

  <http://www.w3.org/2007/OWL/wiki/index.php?title=RDF-Based_Semantics&diff=13164&oldid=13156>

>>   Semantic Conditions, Intro:
>>   """
>>   Editorial suggestion: this is a very long section.
>>   For better readability, I would like to suggest to
>>   add some subsection titles. For example,
>>   table 4.1-4.4 are "Classes and Properties",
>>   4.5-4.7 are class construction, etc.
>>   """
>>
>> Originally, I /had/ such subsections. But I then decided against
>having them for the following reasons: First, I think the tables
>themselves are quite good as replacements for subsections. They all have
>a title and a short intro, and there is not much cross referencing
>within the section. Second, in OWL Full it is not so clear as in OWL DL
>what grouping one should choose (there are not really "class
>expressions", for example).
>>
>agree now.

Ok, then I remove this Review Comment and my EdNote on this. 

  <http://www.w3.org/2007/OWL/wiki/index.php?title=RDF-Based_Semantics&diff=13165&oldid=13164>

>>   Semantic Conditions for Restrictions:
>>   """
>>   Shall IOT and IOR be also kept? For example, in table 4.7, we can be
>more precise that y\in IOT and x\in IOR.
>>   """

[...]

>> Regarding your argument of being more precise, this is not really
>true. "y in IOT" means exactly the same as "y in IR", as argued above.
>Currently, there is only "{y|...". One could say "{y in IR|..." instead.
>However, what I have done to address this concern is to add some text on
>"conventions" at the beginning of the section on "Semantic Conditions".
>Please have a look and tell me whether you think that this is
>sufficient.
>>
>That's helpful. A minor suggestion is to use bold font or else to
>highlight the word "convention".

Ok, added a paragraph headline:

  <http://www.w3.org/2007/OWL/wiki/index.php?title=RDF-Based_Semantics&diff=13166&oldid=13165>

>> The other point, "x in IOR", or, equivalently, "x in
>ICEXT(IS(owl:Restriction))", does not need to be stated on the RHS of
>the entries in the "Restrictions" table, since this fact already follows
>from table 4.4 ("Properties"). For example, see the first entry for
>"owl:allValuesFrom". For owl:SelfRestriction, you can find the relevant
>information in table 4.3 ("Classes").
>>
>Right. But explicitly mention this fact again at table 4.7 will make
>it even more clear, e.g., saying "Please note that x in
>ICEXT(IS(owl:Restriction)) in all following conditions."

Ok, but this "problem" is more general and does not only affect the Restrictions table. So I have added some text at the beginning of the "Semantic Conditions" section, taking the Restrictions case as an example:

  <http://www.w3.org/2007/OWL/wiki/index.php?title=RDF-Based_Semantics&diff=13167&oldid=13166>

>>   Semantic Conditions, owl:members
>>   """
>>   Can we make its domain more explicit?
>>   to be the union of {ICEXT(IS(E)) where E is
>>   owl:AllDisjointClasses or owl:AllDisjointProperties
>>   or owl:AllDifferent
>>   """
>>
>> This is a similar question which Zhe put for ILIST. My answer there
>was that I don't want to have too complex sets in the "axiomatic
>triples". Think about how to state this in triple form! The better way
>to handle this would be to define an upper class for all the different
>"All*" classes. But that's a matter of the OWL 2 RDF Syntax, OWL 2 Full
>shouldn't try to fix around too much here.
>>
>I see the point. I checked again and saw actually the type information
>of the list can be obtained from other tables, e.g., Table 4.12 for
>owl:AllDisjointClasses.

Yes, for example, the members of the argument list in a AllDisjointClasses axiom are really entailed to be classes. This should always be the case (if you find a counter example, tell me please, because this might be a bug). The only problem is that you need to have the whole construct somewhere in your ontology, in order to receive this entailment; the information is not true in the empty RDF graph. Just as a remark for those who care. :-)   

>>   Semantic Conditions, Axiom Annotations
>>   """
>>   add x in ICEXT(IS(owl:Axiom)) union ICEXT(IS(owl:Annotation))
>>   """

[...]

>In fact, I support your Editor's Note before current Table 4.17, i.e.,
>removing the typing triples. This will allow annotations in OWL full
>on any triples. So far I don't see a problem without the  typing
>triples in inference.

Ah, good point! I almost forgot that people might like to annotate statements in OWL Full, either. :-)

Of course, nothing stops me from adding these typing triples in Full, even if I annotate arbitrary triples. The typing triples may at least be /informative/ in Full to distinguish between intended axiom annotations and meta annotations. But, on the other hand, should we /require/ their existence to make the semantic condition fire the base triple? Well, anyway, I have added your comment to my EdNote: 

  <http://www.w3.org/2007/OWL/wiki/index.php?title=RDF-Based_Semantics&diff=13168&oldid=13167>

>>   Relationship to OWL 2 DL
>>   """
>>   Is this section normative or informative?
>>   I believe in OWL 1 Full, comprehension conditions are normative.
>>   """
>>
>> The role of the comprehension principles has changed in the current
>draft of OWL 2 Full, but this doesn't make them simply "informative".
>
>*Finally* we will add "informative" and "normative" to each section's
>title, following RDF and OWL 1 traditions.

I added this suggestion near the beginning of the document:

  <http://www.w3.org/2007/OWL/wiki/index.php?title=RDF-Based_Semantics&diff=13169&oldid=13168>

>> [discussion of role of comprehension principles]
> 
>I need to dig more to fully understand this. I'm reading this now
>
>Carroll, Jeremy; Turner, Dave. The Consistency of OWL Full. Technical
>Reports HPL-2008-58 . HP Lab, 2008.
>http://www.hpl.hp.com/techreports/2008/HPL-2008-58.html
>
>BTW, will it be a proper citation to the discussion in section 6?

I only want to list documents and results in the references section, on which the RDF-Based Semantics actually depends in some form (for example the RDF Semantics), or where there exists a close connection between the two documents, which is relevant for the OWL standard as a whole (for example, the relationship between "RDF-Based Semantics" and "Conformance and Testcases"). This is not given here.

>Thank you again Michael, my questions are well addressed!
>
>Jie

Cheers,
Michael

--
Dipl.-Inform. Michael Schneider
FZI Forschungszentrum Informatik Karlsruhe
Abtl. Information Process Engineering (IPE)
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Email: Michael.Schneider@fzi.de
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Received on Wednesday, 17 September 2008 12:43:03 UTC

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