- From: Dan Connolly <connolly@w3.org>
- Date: Wed, 22 Feb 2006 07:31:00 -0600
- To: Dan Brickley <danbri@danbri.org>
- Cc: public-swbp-wg@w3.org
On Tue, 2006-02-21 at 19:24 -0500, Dan Brickley wrote: > * Dan Connolly <connolly@w3.org> [2006-02-21 18:05-0600] > > > > I just found > > http://www.isi.edu/~pan/SWBP/time-ontology-note/time-ontology-note.html > > via WG minutes and such. > > > > :TemporalEntity > > a owl:Class ; > > rdfs:subClassOf :TemporalThing ; > > owl:equivalentClass > > [ a owl:Class ; > > owl:unionOf (:Instant :Interval) > > ] . > > > > and the domain/range of intBefore is constrained to TemporalEntity. > > So I can't just say > > :conference1 swbp-time:intBefore :conference2. > > without implying that :conference1 is an :Instant or :Interval. > > I have to have some property that relates a conference to > > a time interval, and then use :intBefore on that. > > > > I can't see any reason for the indirection. > > > > The cyc ontology seems to express all the relevant stuff > > without this constraint. The cyc after relationship > > applies to not only instants and intervals, but also > > conferences, meetings, people, etc. > > > > http://www.cyc.com/cycdoc/vocab/time-vocab.html#after > > I can imagine that 'afterness' might mean slightly different things > when relating different types of entity. So doing away with the > indirection is tempting. But sometimes a thing is a member of multiple > independent classes; eg. be both an xyz:Person, an abc:Employee and > cde:RFIDTaggedEntity. Since we can't rely on typing information always > being present, this makes me wary of overloading 'after', since > multiple class membership could bring different interpretations of > afterness to bear. I don't see how multiple types or lack of information is relevant. It's constraints that lead to inconsistencies that I want to avoid. > > That said, from the definition at > http://www.cyc.com/cycdoc/vocab/time-vocab.html#after I don't see > how it applies to people, meetings and random other types, > "A #$PrimitiveTemporalPredicate that relates two points in time. > (#$after LATER EARLIER) means #$TimePoint LATER is after (occurs later > in time than) #$TimePoint EARLIER." > Does some other bit of Cyc model people, conferences etc as 'time > points'? Or am I missing something obvious? oops; wrong one. The ones I tend to use are... http://www.cyc.com/cycdoc/vocab/time-vocab.html#$startsDuring http://www.cyc.com/cycdoc/vocab/time-vocab.html#temporallySubsumes http://www.cyc.com/cycdoc/vocab/time-vocab.html#temporalBoundsContain hmm... those seem to be defined in terms of after and http://www.cyc.com/cycdoc/vocab/time-vocab.html#startingPoint e.g. http://www.cyc.com/cycdoc/vocab/time-vocab.html#$startsAfterEndingOf "Thus it is equivalent to the form (#$after (#$StartFn AFTER) (#$EndFn BEFORE))." so I suppose the cyc design uses an indirection too; but the TemporalThing class is _not_ constrained to be an instant or interval. http://www.cyc.com/cycdoc/vocab/time-vocab.html#TemporalThing > > Dan -- Dan Connolly, W3C http://www.w3.org/People/Connolly/ D3C2 887B 0F92 6005 C541 0875 0F91 96DE 6E52 C29E
Received on Wednesday, 22 February 2006 13:31:14 UTC