- From: Dan Brickley <danbri@danbri.org>
- Date: Tue, 21 Feb 2006 19:24:31 -0500
- To: Dan Connolly <connolly@w3.org>
- Cc: public-swbp-wg@w3.org
* 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. 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? Dan
Received on Wednesday, 22 February 2006 00:24:39 UTC