- From: Gary Hallmark <gary.hallmark@oracle.com>
- Date: Fri, 17 Oct 2008 09:53:27 -0700
- To: Christian de Sainte Marie <csma@ilog.fr>
- CC: rif WG <public-rif-wg@w3.org>

No, I do not want to consider the FPWD. I expect that editors are working on the latest version that is maintained on the wiki, and I expect that editors don't have a private offline copy with extensive changes. Changes should me made visible at least daily. We agreed in the last telecon that we would each review the wiki version. I have identified issues that need to be addressed. For additional visibility into the PRD editing process, my issues may generate resolutions about what/how to modify the document, and actions about who will modify the document. Christian de Sainte Marie wrote: > > Gary and all, > > I just browsed through your comments, yet, so this is only a quick > comment re the subject: trying the semantics with examples is a very > good thing, indeed. But I suggest that you try the semantics in the > July FPWD, or wait a couple more days for the current wiki version to > be updated. > > Just as a reminder: although there is no specific warning in the > current draft on the wiki, the "rules and ruleset" section is not > uptodate, as I said during the PRD telecon (but maybe not clearly > enough). > > It is mostly the version that was published in July, with a couple ad > hoc changes, but not aligned with the remainder of the document > anymore. E.g., as Gary notices, the notion of an instance of a rule is > still used, but it is not defined anymore, etc. > > My understanding was that that part (the semantics of rulesets, > including conflict resolution) would be the main subject of our > discussion in Orlando, and I planned to have it tidied by next Tuesday. > > Gary, actually, I think that it would be interesting if you could try > your example on the smenatics as it is described in the FPWD, since I > do not plan to change anything re the content, only align the form to > the editorial changes in the other parts of the document. > > Cheers, > > Christian > > Gary Hallmark wrote: > >> >> >> This is a case-oriented review of the current PRD spec on the wiki. >> It attempts to use the spec to give meaning to >> the following simple ruleset, and identifies a number of issues >> uncovered. Overall, I'm encouraged that the spec >> generally seems to "work" -- many of the issues are largely editorial >> (save for the problems with PICK, which I address >> somewhat here and in detail in a seperate email. >> >> Prefix(p someIRI) >> p:A(0) >> (* r1 *)Forall ?x (p:A(?x) :- p:A(External(func:numeric-minus(?x 1)))) >> >> >> Issue 1: We must state that all "initial facts" in the ruleset RS >> (here, p:A(0)) are removed from RS and become the initial working >> memory w<sub>0</sub> >> >> so, after this step, we have >> >> w = {p:A(0)} >> RS = (* r1 *)Forall ?x (p:A(?x) :- p:A(External(func:numeric-minus(?x >> 1)))) >> c = (w, {}, nil, nil) i.e. the initial configuration is the initial >> facts and an empty set of rule instances. >> We have added a third component to the configuration: the rule >> instance that is picked. >> >> Now, we execute the first cycle of the transistion system. >> >> s = {} because instances(c) is {} >> c' = (w, INSTANTIATE(w, RS), PICK(LIFO, c)) >> >> Issue 2: INSTANTIATE returns a set of Inst(R). This is undefined. >> I guess it is a pair (rule-id, consistent-substitution), and that >> furthermore it must return *all* such pairs. >> >> Issue 3: picked(c) from my new PICK specification should be changed >> to mean the rule instance picked >> from the prior configuration to arrive at the current configuration. >> And the transistion system that calls PICK must >> save the returned rule instance as picked(c'). >> >> So, >> >> c' = (w, (r1, {?x->1}), nil) >> >> Now, the second cycle >> >> s = extractActions((r1, {?x->1})) because PICK is trivial - only 1 >> rule instance exists >> >> Issue 4: extractActions seems a bit underspecified as to how it >> "grounds" the actions in the rules, >> which may have variables. Also, its argument should be a single rule >> instance, not a list. >> I guess it is supposed to "plug in" the substitutions, so >> >> s = {p:A(1)} >> >> Now, the RIF-PRD transition system says >> >> ({p:A(0)}, p:A(1), w') →RIF-PRD if and only if, for every ground >> formula φ in W, >> w' |= φ if and only if And({p:A(0)} p:A(1)) |= φ >> >> Issue 5: And(...) is undefined. We must define the PS before the >> semantics if we use the PS in the semantics. >> Also, this And takes a set as its first argument. I'll replace the >> set with its member: >> >> ({p:A(0)}, p:A(1), w') →RIF-PRD if and only if, for every ground >> formula φ in W, >> w' |= φ if and only if And(p:A(0) p:A(1)) |= φ >> >> w' = {p:A(0) p:A(1)} >> >> Note: w' is not uniquely determined. E.g. w' = {And(1=1 p:A(0) >> p:A(1))} is ok, too. I guess this is fine. >> >> c' = (w', INSTANTIATE(w', RS), (r1, {?x->1})) = ({p:A(0) p:A(1)}, >> {(r1, {?x->1}), (r1, {?x->2})}, (r1, {?x->1})) >> >> Now, the third cycle. Interesting because we need to pick one of the >> two rule instances. >> >> Issue 6: PICK is ill-defined. >> See my email proposal. According to the new specification, assuming >> the rule is declared as repeatable, the agenda is: >> >> {(0, 0, (r1, {?x->2}))} >> and thus its only rule instance is returned. >> >> s = {p:A(2)} >> w' = {p:A(0) p:A(1) p:A(2)} >> c' = ({p:A(0) p:A(1) p:A(2)}, {(r1, {?x->1}), (r1, {?x->2}), (r1, >> {?x->3})}, (r1, {?x->2})) >> >> Note that if r1 is declared *not* repeatable, then the agenda would >> be empty in the third cycle and the system terminates. >> >> >> >> > > >

Received on Friday, 17 October 2008 16:55:31 UTC