RE: N3 contexts vs RDF reification

I could of sworn you just explained how to provide relationships between RDF
metadata ontologies.

-----Original Message-----
[]On Behalf Of pat hayes
Sent: 26 April 2001 18:00
To: Lee Jonas
Cc: 'Seth Russell';; Tim Berners-Lee; Guha
Subject: RE: N3 contexts vs RDF reification

>My understanding:
>There are at least two competing proposals for representing contexts in
>The concept of 'context', although similar, differs slightly with respect
>'higher-order' statements, ('reification' and making statements about

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

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Received on Thursday, 26 April 2001 14:16:03 UTC