- From: David Allsopp <dallsopp@signal.dera.gov.uk>
- Date: Fri, 18 May 2001 10:36:36 +0100
- CC: www-rdf-logic@w3.org
pat hayes wrote: > ...the problem is not being able to say > all these good things about assertions: it is that triples (alone) > are not adequate to be the assertions. They are too SMALL. They don't > let me say what I want to be able to say: they don't let me say (NOT > ...) or (... OR ....) or (EVERY .... IS ....). These kinds of > assertions need more than single triples, you see, because they have > more than three parts. A simple point, surely? (And please don't tell > me that you can do this with "reification". I know, I know: read on.) Ah, light dawns - that clears up my questions in yesterdays email too; thank you. So the RDF dilemma is that either A) we stick to very trivial things expressible with single triples or B) attempt to feed an inference engine a mixture of assertions and syntactic sugar, and watch it choke...8-) > Now, you can always take one of these more-than-triple things and > hack up a structure of triples to encode it, sure. So in a sense you > can think of the knowledge as a set of triples, or at least encoded > in a set of triples. But then that encoding is NOT A LOGICAL > CONJUNCTION. It is a data-structure which is being used to represent > a piece of syntax. Again, I have no problem with that either. > What I do have a problem with is getting these confused with one > another: with a notation (like RDF) that says that it is just > conjunctions of triple-style atomic assertions, but also wants to be > a datastructure language for encoding more complex assertions. You > can't have it both ways... Regards, David Allsopp. -- /d{def}def/u{dup}d[0 -185 u 0 300 u]concat/q 5e-3 d/m{mul}d/z{A u m B u m}d/r{rlineto}d/X -2 q 1{d/Y -2 q 2{d/A 0 d/B 0 d 64 -1 1{/f exch d/B A/A z sub X add d B 2 m m Y add d z add 4 gt{exit}if/f 64 d}for f 64 div setgray X Y moveto 0 q neg u 0 0 q u 0 r r r r fill/Y}for/X}for showpage
Received on Friday, 18 May 2001 05:40:58 UTC