From: Benjamin Grosof (bgrosof@MIT.EDU)
Date: 07/01/03
% notes from JC telecon 6/24/03 % by Benjamin Grosof o rule test cases: Mike has a bunch of wish cases, e.g., about equivalence e.g., using sameIndividualAs or cardinality-1 he's working on an engine that has some knowledge of OWL, and uses N3 syntax, that can do some of the rule test cases todo: talk with Mike about integrating his ideas/prototype with the SweetOnto/KAON work on DLP (Description Logic Programs) which was demo'd by Boris Motik at WWW-2003 semantic web developers day Benj: wrt style: suggestion: more prose comments, organize by point made, e.g., domesticflight-1.n3 and uncle-1.n3 and siblingfather-1.n3 all give examples of ontological knowledge that are hard/impossible to express in OWL-DL "<>" denotes the current KB discussion about whether equality should be treated explicitly, and defined by rules, vs. built into the language/engine Benj: we obviously want the capability for the latter, but recommend the former as one available compliance level in the beginning, for flexibility, since many practical rule systems do not have it built in already with the full strength of FOL semantics Mike: this issue is very related to whether our requirement for the rule language is to extend OWL vs. to work optionally with OWL Mike's approach builds in knowledge of OWL to the rule language and system Benj: let's list this as an objective Benj: SweetOnto/KAON implementation that we have right now first translates OWL/DL stuff into LP, then does inferencing in an LP rule system; but it's nice to have the OWL syntax (say, for DLP expressive subset) supported Benj during discussion with Pat: nonmon about equality, say default distinctness via NAF, is not well studied in the KR literature, so it would be more cautious (wrt sticking to what's already well understood) to define equality as an ordinary predicate and then explicitly axiomatize its substitutivity, transitivity, symmetry Pat: but can't we rely on NAF as a mechanism to define nonmon aspects of equality? Benj: yes, that's the direction I would take Benj: wrt more test cases beyond DLP: - for ontological knowledge, e.g., in MIT Process Handbook or various frame-based systems, often want nonmonotonic inheritance, thus beyond DLP - it's pretty easy to give examples of cardinality or disjunction or existentials that go expressively beyond the current version of DLP Pat in discussion with Mike and Benj: let's aim to have some OWL syntax directly within the rule language Benj: yes, this is a large motivation of the DLP work, but this might be beyond our V1 because it involves more complexity consensus: yes; need RDF syntax for the rule language, and a corresponding human presentation syntax e.g. cf. N3 Pat: wrt syntaxes, let's look at TRIPLE by Stefan Decker and Michael Sintek ________________________________________________________________________________________________ Prof. Benjamin Grosof Web Technologies for E-Commerce, Business Policies, E-Contracting, Rules, XML, Agents, Semantic Web Services MIT Sloan School of Management, Information Technology group http://ebusiness.mit.edu/bgrosof or http://www.mit.edu/~bgrosof
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