RE: Please review OWL-Time document

On Monday, February 20, 2017 3:46 AM, Simon.Cox@csiro.au [mailto:Simon.Cox@csiro.au] wrote:

> Regarding ISSUE-125 and ISSUE-126
> 
> I have followed Lars suggestion and added :inXSDDateTimeStamp to complement
> :inXSDDateTime and have annotated the latter owl:deprecated="true"
> This should improve computability while protecting legacy instances.
> 
> If I hear no objections by the end of the week, I'll close these two issues.

Thanks Simon, that's +1 from me.

Lars
 
> -----Original Message-----
> From: Svensson, Lars [mailto:L.Svensson@dnb.de]
> Sent: Thursday, 12 January, 2017 19:34
> To: Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au>
> Cc: public-sdw-wg@w3.org
> Subject: RE: Please review OWL-Time document
> 
> Hello Simon,
> 
> On Wednesday, January 11, 2017 10:39 PM, Simon.Cox@csiro.au
> [mailto:Simon.Cox@csiro.au] wrote:
> 
> > 1) Actually there is no domain or range for time:after, just the
> > inverseOf relationship to time:before which does have them.
> > Of course the domain and range is implied by the inverseOf relationship.
> > But I'm not sure what the current recommended style is - in 2006 I
> > guess domain and range were omitted if an inverseOf relationship was declared.
> > But it requires a reasoner to understand this. Is there a general
> > assumption that reasoning shall always be assumed?
> 
> Perhaps we can always assume reasoning, but not always OWL reasoning (although it's
> named OWL Time wo perhaps we _can_ assume that...). If I remember the discussion
> about SSN and SOSA correctly, we wanted to keep the option open to perform RDFS
> reasoning only (and thus added rdfs:Class and rdfs:Property at the appropriate places)
> and people more knowledgeable than me can probably tell if that makes sense here,
> too.
> >
> > I had not intended to change this (though I had mistakenly added a
> > domain and range for time:after in the ttl file, which I have now reverted).
> > If the group thinks a change is merited, then I am happy to insert
> > domains and ranges all round where they are already implied by inverseOf
> relationships.
> 
> Yes, an OWL reasoner can of course infer the correct domain and range from the
> owl:inverseOf relation, but an RDFS reasoner can't. I guess it boils down to the
> question if it makes sense to use OWL Time without OWL.
> 
> > 2) Processed.
> 
> Thanks.
> 
> > 3)   Regarding ISSUE-125 - I agree that xsd:dateTimeStamp is preferable, but the
> > problem is backward compatibility.
> > If the rdfs:range of inXSDDateTime is changed from xsd:dateTime (which
> > is still part of OWL2 btw) to xsd:dateTimeStamp, then what are the
> > implications for existing data in which the timezone is omitted?
> > Does it become 'invalid' in some way?
> 
> Ah, now I understand: it's about existing instance data. Could it be a solution to mark
> time:inXSDDateTime as deprecated and add a new property
> time:inXSDDateTimeStamp with range xsd:dateTimeStamp and domain time:Instant?
> That way existing data would still be valid while we communicate that it's not good
> practice to use time:inXSDDateTime anymore.
> 
> Best,
> 
> Lars
> 
> > -----Original Message-----
> > From: Svensson, Lars [mailto:L.Svensson@dnb.de]
> > Sent: Thursday, 12 January, 2017 07:43
> > To: Cox, Simon (L&W, Clayton) <Simon.Cox@csiro.au>;
> > public-sdw-wg@w3.org
> > Subject: RE: Please review OWL-Time document
> >
> > Simon, all,
> >
> > On Thursday, December 22, 2016 6:37 AM, Simon.Cox@csiro.au
> > [mailto:Simon.Cox@csiro.au] wrote:
> >
> > > The Editors draft of the OWL-Time specification can be considered
> > > for release as a second public working draft.
> > > http://w3c.github.io/sdw/time/
> >
> > I use the time after today's super-short meeting to make some very
> > minor comments on this very concise and informative document: cudos to the
> editors!
> >
> > 1)	time:before has domain and range time:TemporalEntity which time:after
> > doesn't. I guess that time:after should have domain and range, too.
> >
> > 2)	There is a typo in the URI given in the OWL-2 reference [1]. The text is ok, but
> > the href says http://www.w3.org/TR/turtle/owl2-quick-reference/#Built-
> in_Datatypes .
> > I think that should be
> > http://www.w3.org/TR/owl2-quick-reference/#Built-in_Datatypes
> >
> > 3)	Regarding ISSUE-125 and backward compatibility with OWL-1, there was a mail
> > from Antoine Zimmermann where he said: "The standard Web Ontology
> > Language is now OWL 2. Let us forget about OWL 1" [2]. So I think it
> > should be safe to update the spec to use xsd:dateTimeStamp.
> >
> > [1] https://w3c.github.io/sdw/time/#OWL-2
> > [2]
> > https://lists.w3.org/Archives/Public/public-sdw-wg/2016Nov/0069.html
> >
> > Best,
> >
> > Lars

Received on Monday, 20 February 2017 10:49:02 UTC