- From: David Allsopp <dallsopp@signal.dera.gov.uk>
- Date: Mon, 09 Apr 2001 15:42:52 +0100
- To: Danny Ayers <danny@panlanka.net>
- CC: www-rdf-logic@w3.org
Danny Ayers wrote: > <- Your scheme above is encoding, not expressing, because RDF has > <- no mechanism > <- that can be used to capture the meaning of negation. > Why does it need to capture the meaning in any case - if machine A > understands a = !b means 'not' and machine B understands a = !b means 'not' > why does the data model have to understand for a message to be conveyed? IANAL*, but I think it's because an arbitrary machine C, which only knows 'standard' RDF, won't understand, and will not be able to process the data in the way intended by A. The data then have different meanings to different machines, which defeats the whole purpose of the semantic web. The negation is not built-in to RDF, so it has no meaning in its own right. The meaning is 'outside' the system, as in Pat Hayes' "punched cards with writing on them". Regards, David Allsopp. *substituting Logician for the usual Lawyer. Proving whether this is an improvement is left an an exercise for the reader. ;-) -- /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 Monday, 9 April 2001 10:46:54 UTC