- From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
- Date: Tue, 7 Feb 2012 01:09:14 +0000
- To: Provenance Working Group <public-prov-wg@w3.org>
> Is the following valid? > > wasGeneratedBy(e,,2001-10-26T21:32:52) > wasGeneratedBy(e,,2011-11-27T21:23:34) You can't write time like that in ASN, they must be quoted literals or kind-a-CURIEs. (And we should choose one of those to use for time in ASN - it seems we already like to talk about t1,t2 etc, but elsewhere claim it is XSD Date time. Given discussions in F2F I would suggest the former.) My interpretation of this is that 2011-11-27T21:23:34 and 2001-10-26T21:32:52 is the same event (the generation event). I don't know what that means, perhaps that the generation is a very slow thing, that the observer's clock has moved but the entity's clock has not (say a frozen computer simulation), that the two times are the same, or that the asserter is plain simply wrong. And so I don't think we should say much about it. It becomes of course much easier to narrow down the possibilities if we separate times and events, as currently done in PROV-O with using the (no longer time:) Instant resources - here you would just say: :e prov:wasGeneratedAt :t1 . :e prov:wasGeneratedAt :t2 . :t1 prov:inXSDDateTime "2001-10-26T21:32:52"^^xsd:dateTime . :t2 prov:inXSDDateTime "2011-11-27T21:23:34"^^xsd:dateTime . (or equivalent long-version with prov:Generation and prov:hadTemporalValue) prov:wasGeneratedAt is functional, because there is only one generation event of an entity. Thus we know that :t1 == :t2 and can limit our trouble-search there - in this case we could get an OWL error because prov:inXSDDateTime is a functional datatype, or not, depending on how strongly we choose to believe the owl:sameAs. -- Stian Soiland-Reyes, myGrid team School of Computer Science The University of Manchester
Received on Tuesday, 7 February 2012 10:30:19 UTC