- From: pat hayes <phayes@ai.uwf.edu>
- Date: Thu, 26 Apr 2001 11:59:53 -0500
- To: Lee Jonas <lee.jonas@cakehouse.co.uk>
- Cc: "'Seth Russell'" <seth@robustai.net>, <www-rdf-interest@w3.org>, Tim Berners-Lee <timbl@w3.org>, Guha <guha@alpiri.com>
> >My understanding: > >Summary >======= >There are at least two competing proposals for representing contexts in RDF. >The concept of 'context', although similar, differs slightly with respect to >'higher-order' statements, ('reification' and making statements about >statements). I wonder, could I make a plea that y'all change your terminology here slightly? The term 'higher-order' already has an accepted usage now for about80 years, and it isn't this, so this is likely to cause all kinds of confusion and wasted time. What you are talking about is meta-language statements (statements about other statements), not higher-order statements. What makes something higher-order is that it involves quantification over a universe of relations or functions, as when you might be able to infer from (P a c) and (Q b c) that there exists a relation [P or Q] which holds between both (a c) and (b c). Often, though not always, higher-order logics use some kind of lambda-conversion. Being higher-order is connected in various ways with set theory (in mathematical logic, relations are sets), and the 'higher' in the name refers to a set-theoretical heirarchy, not a language/metalanguage heirarchy. These havn't got much to do with one another, and I don't think that being higher-order is likely to be of much interest to RDF or Web logics more generally. Traditional logic has studied higher-order logics and set theory in excruciating detail, but it hasnt paid quite so much attention to language/meta-language heirarchies. Pat Hayes --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Thursday, 26 April 2001 13:00:03 UTC