- From: Seth Russell <seth@robustai.net>
- Date: Thu, 24 Jan 2002 14:26:21 -0800
- To: "RDF-LOGIC" <www-rdf-logic@w3.org>
- Cc: "Pat Hayes" <phayes@ai.uwf.edu>
At http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Jan/0257.html Pat Hayes said: [[ The trouble with this kind of approach (not to reification in particular, but more generally) is that if there is no way in the language to state a distinction, and if the same constructs are used to say different kinds of things, then confusion will be inevitable. Maybe some people will manage to get by, but someone else will be confused (or, worse, some other piece of software will get confused.) Surely it is better to provide a way to state or somehow indicate the distinction [*1], and allow both kinds of things to be said more clearly. If you want strict backward compatibility and don't like new syntactic conventions, then make the one you like best be the unmarked case and mark the other one. ... ]] Would you agree that whatever a reification node is, it is certainly is a blank node? _:s1 rdf:type rdf:Statement _:s1 rdf:predicate :pred _:s1 rdf:subject :sub _:s1 rdf:object :obj Doesn't the MT say that a blank node simply indicates "the existence of a thing". So the Ntriples above just say: (exists (?x) (and (rdf:type ?x rdf:Statement) (rdf:predicate ?x :pred) (rdf:subject ?x :subject) (rdf:object ?x :obj) )) So our interpretation is any of the things which qualify according to the above formula that exist in our universe. If we want to further qualify those things to statings in a particular document, then we could add further restraints to the formula like: (exists (?x) (and (rdf:type ?x rdf:Statement) (rdf:predicate ?x :pred) (rdf:subject ?x :subject) (rdf:object ?x :obj) (dc:auther ?x :Seth) (dc:document ?x "http://foo/bar.rdf" ) )) My question is: Does considering reified statements to be the blank nodes ("existential assertions") means that we can draw whatever distinctions your refer to above [*1] with additional Ntriples on the same blank node identifier ... and that it is not necessary for the MT to further refine the definition ... but rather allow the user to draw those distinctions with additional triples? (no mentograph necessary) Seth Russell
Received on Thursday, 24 January 2002 17:29:26 UTC