- From: Pat Hayes <phayes@ihmc.us>
- Date: Fri, 16 Nov 2012 17:02:57 -0800
- To: Richard Cyganiak <richard@cyganiak.de>
- Cc: Pierre-Antoine Champin <pierre-antoine.champin@liris.cnrs.fr>, Antoine Zimmermann <antoine.zimmermann@emse.fr>, RDF Working Group WG <public-rdf-wg@w3.org>
On Nov 16, 2012, at 6:28 AM, Richard Cyganiak wrote: > On 15 Nov 2012, at 21:29, Pat Hayes wrote: >> I like this ecept I'd like to keep the term "simple entailment" for the basic graph-level case, and so have this: >> >> 1. SImple Entailment >> IRIs >> blank nodes >> triples >> graphs >> >> 2. RDF with literals >> Datatype map >> Typed literals >> rdf:langString >> >> 3. RDFS (including datatypes-as-classes, if you like: I agree might as well merge these.) > > Okay, I guess Simple Entailment should be retained. > > Just to be really clear here: I suppose this means that Simple Entailment would still say: > > * if E is a language-tagged string "aaa"@ttt in V, then I(E) = <aaa, ttt> > * if E is a literal in V that is not a language-tagged string, then I(E) = IL(E) Yes. > Because that's essentially the translation of the current Simple Entailment conditions for literals to the new design. Right. So semantics recognizes four kinds of 'node': IRIs, language-tagged literals, typed literals, and blank nodes IDs. (It refers to bnode scopes in giving the truth conditions for bnodeIDs) > And then RDF-with-literals Entailment would just add a single condition, something like (assuming we don't change the handling of ill-typed literals): > > * if <aaa,x> is in D then for any literal "sss"^^ddd in V with I(ddd) = x , > if sss is in the lexical space of x then IL("sss"^^ddd) = L2V(x)(sss), > otherwise IL("sss"^^ddd) is not in LV or, ( not in LV // undefined ) if we do change it. Yes. > So, technically speaking, rdf:langString would be handled in Simple Entailment, because that's the datatype that distinguishes language-tagged strings from other literals, and is the only datatype that isn't handled via the datatype map. Yes, I guess you are right. I don't think there are any axioms or rules that depend upon just this case, so the simple entailment lemma will still work. > > (See here: > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#section-Graph-Literal > And the second note here: > http://dvcs.w3.org/hg/rdf/raw-file/default/rdf-concepts/index.html#section-Datatypes ) > > All the other conditions (starting to take the meaning of specific IRIs into account, other than the IRIs in the datatype map) would then be in RDFS-entailment. > > That would work for me. Sounds like we are in violent agreement :-) Putting all of this into RDFS-entailment means that entailment regimes no longer correspond exactly to namespaces, however (because of rdf:type not rdfs:type). Some people will, I predict, not like this. We ought to call it out in any case as it will confuse some readers. > > Background: This should make it possible to take the informative entailment rules out of Semantics, and put those for Simple Entailment and RDF-with-literals Entailment as an appendix into RDF Concepts, and those for RDFS Entailment into RDF Schema, each time with a clear statement that the normative form is the model theory found in RDF Semantics. Yes, I guess :-) Pat > > Best, > Richard > ------------------------------------------------------------ IHMC (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32502 (850)291 0667 mobile phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Received on Saturday, 17 November 2012 01:03:32 UTC