- From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Date: Fri, 21 Jun 2002 16:27:16 +0100
- To: Jan Grant <Jan.Grant@bristol.ac.uk>
- Cc: RDFCore Working Group <w3c-rdfcore-wg@w3.org>
At 06:59 PM 6/18/02 +0100, Jan Grant wrote: >Pat indicated at the F2F that entailments "accidentally" drawn would be >"harmless". Can someone clear up this example for me? > >A: > <eg:foo1> <rdf:subPropertyOf> <dark:eg:foo2> . > <dark:eg:foo2> <rdf:subProperotyOf> <eg:foo3> . > > <eg:a> <eg:foo1> <eg:b> . > >B: > <eg:foo1> <rdf:subPropertyOf> <dark:eg:foo2> . > <dark:eg:foo2> <rdf:subProperotyOf> <eg:foo3> . > > <eg:a> <dark:eg:foo2> <eg:b> . > >C: > <eg:foo1> <rdf:subPropertyOf> <dark:eg:foo2> . > <dark:eg:foo2> <rdf:subProperotyOf> <eg:foo3> . > > <eg:a> <eg:foo3> <eg:b> . > > >Does A |= C? Does A |= B? B |= C? > >Awaitening en(light|dark)enment, >jan My opinions: A |= B: yes. B |= C: no. (e.g. consider interpretation in which all relational extensions are empty.) A |= C: Hmmm. I think the answer is yes. I think the model theory constrains the relational extensions of eg:foo1, dark:eg:foo2 and eg:foo3 to have a subset relationship, even though the relational extension of dark:eg:foo2 does not affect the truth of any graph that uses it. Which leads to the interesting observation that entailment is not transitive, which I inituitively expect it to be. Good question! I don't remember the context of accidental entailments mentioned, so cannot comment further. #g ------------------- Graham Klyne <GK@NineByNine.org>
Received on Friday, 21 June 2002 11:31:06 UTC