- From: pat hayes <phayes@ai.uwf.edu>
- Date: Tue, 4 Sep 2001 12:55:53 -0700
- To: Dan Connolly <connolly@w3.org>
- Cc: w3c-rdfcore-wg@w3.org
>Jan Grant wrote: >[...] > > While I have held, in principle, what I'd characterise as DanC's opinion > > here (or the more extreme version: "alt is totally broken") > >I'm not saying it's broken; I'm just saying it's not magic. >It's very mundane; from the MT perspective, >it means no more or less than any >other class (Apple, Bananna, Integer, ...). Then why bother even mentioning it in the M&S, let along spending pages on it? The M&S doesn't seem to feel a compulsion to go on and on about recommended uses of Bananas. > > - that is, > > that an app can infer what it likes, an alt-unaware MT is going to > > produce an odd semantics for something like > > > > <doc1> <dc:creator> _:a . > > _:a <rdf:type> <rdf:Alt> . > > _:a <rdf:_1> <jan> . > > _:a <rdf:_2> <dan> . > > > > ("doc1 was written by either jan or dan") - I don't see how you can > > ignore alt in the MT and get this interpretation, no matter how you go > > about it. > >I interpret that n-triples fragment not as "doc1 was written >by either jan or dan" but > > doc1's has a creator value which is a collection including > jan and dan; this collection is the sort where folks conventionally >choose > one from the collection, rather than using all of them. > >Again, suppose the graph had a Bag rather than an Alt: > > <doc1> <dc:creator> _:a . > _:a <rdf:type> <rdf:Bag> . > _:a <rdf:_1> <jan> . > _:a <rdf:_2> <dan> . > >We don't license the inference that > <doc1> <dc:creator> <jan>. >in that case, do we? No. Then why should rdf:Alt have any magic >associated with it? Because that is what the M&S seems to imply, seemed to me; and because if we can't infer anything different from its being an Alt than a Bag, why does the language have both constructs in it? It's not a question of 'magic', but of understanding why there would be a totally meaningless distinction built into the syntax. This line amounts to treating all containers alike in the MT, ie they are thingies that have elements which are accessed by applying rdf:_n to them, and that's all. The only differences between bags and seqs and alts is that they are different by stipulation, ie nothing can be both of them at once. However, if we do say this, then it seems question-begging (and intellectually dishonest) to go on to say that some aspect of meaning is 'conventionally' this or that, when the language itself doesn't support that 'conventional' interpretation. In other words, we are saying that it *does* mean something, nudge nudge wink wink, but *we* aren't going to come out and say what it does mean, for some reason. (Not that we couldn't: we can, in fact, but we are refusing to, for some reason, probably because ... well, I cannot think why, to be honest. ) This seems to me to be exactly the wrong way to set up a useful semantic-web information interchange language. Pat --------------------------------------------------------------------- (650)859 6569 w (650)494 3973 h (until September) phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Tuesday, 4 September 2001 15:54:37 UTC