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Re: ISSUE-24, ISSUE-21: Versioning language

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 18 Jun 2008 08:50:43 -0400 (EDT)
Message-Id: <20080618.085043.100500702.pfps@research.bell-labs.com>
To: alanruttenberg@gmail.com
Cc: boris.motik@comlab.ox.ac.uk, ian.horrocks@comlab.ox.ac.uk, public-owl-wg@w3.org

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Subject: ISSUE-24, ISSUE-21: Versioning language
Date: Wed, 18 Jun 2008 01:35:12 -0400

> Changes below: Mostly to tighten up the shoulds and mays, which are
> bolded, and to add an explicit must not to say you can't load the latest
> version if a specific version is asked for. [I comment on this change
> below.] Also, make clear what
> happens if the import doesn't match the ou or vu to match what happens
> in other cases, removing the mention of what OWL tools should
> do. [I comment on this change below as well.] Removed the word
> "typically" because the atypical case is not 
> spelled out. Tried to standardize on the word "access" for what you do
> to get an ontology from a location. I'd probably try to replace the
> "physical location" wording similarly, if I had more time now.
> 
> I'm not thrilled about owl:incompatible with only being able to have the
> subject the ontology in the header. This would not have been a
> restriction in OWL 1.  
Yes, but in OWL 1 there were problems with determining which ontology
node was the ontology node for the current ontology.  Arbitrary
owl:incompatibleWith would bring this back.
> I'd rather one be able to specify anywhere that
> one ontology version is incompatible with another. I'd suggest
> decoupling the incompatibleWith statements from the header by having a
> form: IncompatibleOntologies(vu-or-ou1 vu-or-ou2) serialized, in RDF, as
> "vu-or-ou1 owl:incompatibleWith vu-or-ou2.", with no logical semantics.
> This means that the wording "Furthermore, if the import closure of O
> contains ontologies O1 and O2 such that O1 contains an ontology
> annotation owl:incompatibleWith with the value equal to either the
> ontology or the version URI of O2, then O should be considered
> syntactically invalid." needs to be changed.
> 
> I consider to be a separate issue the question of whether all OWL
> documents must have an ontology header, and don't consider that issue
> resolved yet. However I don't think that issue impacts the wording here.
> 
> These are the substantive issues that I would like to agree to in
> principle - 
Umm which are the substantive issues?  It's not clear to me.
> though not necessary do all the edits - before resolving. I
> don't think that they differ from the spirit of what is being proposed,
> though better to make sure. In addition there is wordsmithing for
> clarity that is a normal part of editing that I will suggest when I
> review the documents. I'm not listing details here, just noting that
> there is some work to do.
> 
> -Alan
> 

[...]


> 3.2
> 
> The ontology and the version URI, if present, determine the physical
> location of an ontology O according to the following rules:
> 
> If O contains a version URI then O must contain an Ontology URI.
> 
> If O does not contain an ontology URI 
> (and, consequently, no version URI), 
> then O may be physically located anywhere.

> If O contains an ontology URI ou but no version URI or contains a
> version URI vu that is the same as ou, then O should be physically
> located at the location ou.

This seems to be covered by the next case perfectly well.  Why bother to
duplicate the rules?

> If O contains an ontology URI ou and a version URI vu 
> that are not the same, 
Remove this qualification to cover the previous case as well.
> then O should be physically located at the location vu and may [also] be
> physically located at the location ou.

> The [current/most recent] version of an ontology series with some URI ou may be
It may be that there will be some reason to have a more-recent version
of an ontology not be at the main location (perhaps for testing?).
> accessed from ou using a suitable Internet protocol. To access a
> particular version of ou, one needs to know that version's version URI
> vu; then, the ontology should be accessed from vu using a suitable
> Internet protocol, 
> and must not be accessed from ou if ou differs from vu.  
This last prohibition doesn't make sense.  Either the ontology is also
accessible at ou, in which case it may be a bad idea to access it from ou,
or the ontology is not accessible at ou, in which case it can't be
accessed from ou.  Where then does the "must" come from?
> If the document accessed from u contains an ontology URI and
> optionally, if it contains a version URI, and neither is u, then the
> importing Ontology should be considered syntactically invalid.
I disagree with this wording.  The original wording was much better - it
left the behaviour of the tool completely open but still noted that
there was some weirdness going on.

> 3.4
> 
> Figure 1 presents the logical view of the import relation, which holds
> between two ontologies. In concrete syntaxes, however, the importing
> ontology only contains a URI identifying the location of the imported
> ontology. This location should be interpreted as specified in Section
> 3.2 in order to access the imported ontology.
> 
Received on Wednesday, 18 June 2008 12:51:47 GMT

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