- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Wed, 30 Sep 2009 17:27:18 +0100
- To: Ivan Herman <ivan@w3.org>
- CC: "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>
Hi Ivan, > I am not formally member of the working group and you only have an > editor's draft (to be sure, I read the one in [1]) so I was not sure > whether it is kosher for me to send errors on the WG's public mailing > list. I chose to send them to you directly; if you prefer to resend this > to the WG list for proper archiving, it is perfectly fine with me... Thanks Ivan. Very helpful to have these problems spotted. I'm copying the WG list for proper archiving. > Here are the few problems I found: > > In 4.3.1 you list the rule eq-diff2. This rule, in the OWL 2 Profile > document, looks like: > > T(?x, rdf:type, owl:AllDifferent) > T(?x, owl:members, ?y) > LIST[?y, ?z1, ..., ?zn] > T(?zi, owl:sameAs, ?zj) > > which does not seem to be identical to the way you quote it: > > T(?yi, owl:sameAs, ?yj) > T(?x, rdf:type, owl:AllDifferent) > LIST[?x, ?y1, ..., ?yn] > > (reference to owl:member is missing altogether...) > > Same issue with prp-adp and cax-adc > > I may miss something here, though, because the impression I have is > that, in the rule transformation in section 7.2, you use the right > owl:members and owl:distinctMembers predicates... Ah yes, these rules were different in the OWL Profiles document when I first produced the document. The section 7.2 was updated as we built the reasoner we reported on; I thought I had migrated all the rules back into the rest of the document but clearly failed on those ones. Fixed. > ------------- > > - In 4.3.1, in the translation to rules you say, for example, for eq-diff2 > > External(pred:list-contains(?l ?x)) ?ix = External(func:index-of(?l ?x)) > External(pred:list-contains(?l ?y)) ?iy = External(func:index-of(?l ?y)) > External( pred:numeric-not-equal ( ?i ?j ) ) > > Shouldn't the last line be > > External( pred:numeric-not-equal ( ?ix ?iy ) ) > > (the same error repeats itself in all four rules) Yes, cut paste error, now fixed. > - Right before 4.3.3. in the second alternatives for property chain the > second rule uses > > ?x[rdf:tl->?y] > > which does not look right, rdf:tl is not in the rdf space... I guess it > should be rdf:last Yes, fixed. Though that alternative form is not used in the appendix. > (I must admit I did not check Appendix 6 whether the same errors are > copy-pasted there, too...) Copy-pasted the newly fixed versions. > -------------- > > I also found some trivial editorial mini-bugs: > > - Section 4.3, second paragraph, 'OWL2 RL' -> 'OWL 2 RL' > - Section 4.3, paragraph right before 4.3.1. 'The' -> 'There' Fixed. > - Section 4.4.2, first rule, it looks to me as if there was a > superfluous ')' after '->l2]'. The same in the more complete, second rule. Actually in that case the bug was a superflous ')' before the ':-', the one at the end is right. I hope I never have to write any of this Presentation Syntax! > -------------- > > Also, though this is more editorial than other... My understanding of > your encoding on the dt-type2 rule (in 4.4.3) is that > > ?lt[rdf:type->?ty rdf:type->rdfs:Literal] > > does actually slightly more than what dt-type2 requires, insofar as it > also generates the (?lt rdf:type rdfs:Literal) which is, strictly > speaking, not in dt-type2. Though it is _correct_ to add it there > because there is a subsumption on that triple, maybe it deserves an > editorial note... I don't agree with this one, though as you say it is more editorial. In the OWL 2 Profiles document dt-type2 says that it asserts T(lt, rdf:type, dt) ""for each literal lt and each datatype dt supported in OWL 2 RL such that the data value of lt is contained in the value space of dt"". The issue is that rdfs:Literal is listed as a supported datatype for OWL 2 RL and since all those literal values are contained in rdfs:Literal then dt-type2 should in fact be asserting those triples as well. If RIF had direct support for rdfs:Literal or had a generic is-literal predicate (or had the original is-literal-of-type predicate) that those rules would be a lot shorter :-) > I hope this is helpful... Very much so, thanks. Dave > > Cheers > > Ivan > > [1] http://www.w3.org/2005/rules/wg/draft/ED-rif-owl-rl-20090929/ >
Received on Wednesday, 30 September 2009 16:28:02 UTC