From: Brian McBride <bwm@hplb.hpl.hp.com>

Date: Mon, 23 Jul 2001 09:14:34 +0100

Message-ID: <3B5BDCEA.6C9C1AB3@hplb.hpl.hp.com>

To: Dan Connolly <connolly@w3.org>

CC: rdf core <w3c-rdfcore-wg@w3.org>

Date: Mon, 23 Jul 2001 09:14:34 +0100

Message-ID: <3B5BDCEA.6C9C1AB3@hplb.hpl.hp.com>

To: Dan Connolly <connolly@w3.org>

CC: rdf core <w3c-rdfcore-wg@w3.org>

Dan Connolly wrote: > > Brian McBride wrote: > [...] > > Looks good, mostly... > > > Here goes: > > > > Let U be the set of URI References (as defined by RDF 2396). > > I don't think you mean that relative URI references > are in U. I think U is the set of absolute URI references; > i.e. URIs with optional #fragment thingies. Yes. > > > //ignore lang and namespaces for now > > Let S be the set of of UNICODE strings (UNICODE*) > > > > An interpretation I consists of: > > > > A set R of thingies > > > > A subset P of thingies which corresponds to Properties > > > > A mapping IN : U -> R > > > > A mapping IEXT : P -> R x R // R cross R > > > > A mapping IS : S -> R > > > > <s> <p> <o> . is true in I if and only if: > > > > s, o are members of U, p is a member of P > > (IN(s), IN(o)) is a member of IEXT(I(P)) > > that last P should be little, no? IEXT(I(p)) Yes > > > <s> <p> "string" . is true in I if and only if: > > > > s is a member of U, p is a member of P and string is a member of S > > (IN(s), IS(string)) is a member of IEXT(I(p)) > > Just 3 major things missing: > > 1. existentials: > > _:x <p> <o> is true in I iff > o is a member of U, p is a member of P, > and there is some thingy tx in I's set of thingies > so that (tx, IN(O)) is a member of IEXT(I(p)) > > The substitution (tx for _:x) is > said to satisfy the triple _:x <p> <o>. > > In general, a substitution has > any number of (thingy for _:name, thingy2 for _:name2, ...) > pairs. There is a followup message to the original with this in - stuff I added that were not in Pat's original notes > > 2. conjunctions > > a list of triples is satisfied by > some substitution if each of the triples > in it is satisfied by that substitution. ditto > > 3. putting it all together > > A list of triples is true in I iff there's some > substitution that satisfies it. Better worded than mine, but ditto > > > Pat goes on to demonstrate a use of this base model theory to > > define the meaning of reification: > [...] > > Pat points out an issue with reification, and I have another, > > but I suggest we get the base model theory sorted out before we get > > into that. > > Yes, let's leave that for a rainy day... > > Just one of Pat's notes seems essential: > > > (Literals are required by law > > to map to a certain subset of thingies in a predefined way, but > > otherwise are treated like any other names.) > > I'd say literals map to themselves. i.e. IS is the > identity function. Could be. Pat did talk about the integer 5 being a literal which is not the same thing as the string "5". I figured we could stay agnostic on this till we get to datatyping. BrianReceived on Monday, 23 July 2001 04:17:11 EDT

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