- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Fri, 16 May 2003 16:59:57 +0100
- To: Thorsten Liebig <liebig@informatik.uni-ulm.de>
- CC: Jeremy Carroll <jjc@hpl.hp.com>, www-webont-wg@w3.org

Thanks for these comments. We've just voted to move test to last call, so I will add your suggested additional tests after last call publication (probably 28th May). With the additional tests I notice you use relatively small numbers but the paper http://kogs-www.informatik.uni-hamburg.de/~haarslev/publications/m4m2.pdf suggest racer is not constrained by the numbers themselves. Do you know if I am correct in thinking that racer could solve examples similar to the ones you suggest but with much large numbers (100s or 1000s). I have some questions about the error you report ... Thorsten Liebig wrote: > I found two bugs in section 7.3.4 Extended Cardinality Testing: > > <description-logic/Manifest902#test>: > The description says: > "This non-entailment can be replicated for any three natural numbers > i, j, k such that i+j < k. In this example, they are chosen as 2, 3 and 6." > but the conclusion is (in Racer syntax): > > (define-primitive-concept nonconclusions902 > (and (at-least 2 p) > (at-least 3 q) > (at-least 6 r))) > > which is indeed satisfiable. > I suppose the following conclusion was intended: > > (define-primitive-concept nonconclusions902 > (and (at-least 2 p) > (at-least 3 q) > (at-most 4 r))) > > But since at-most represents a "less or equal" condition > (http://www.w3.org/TR/owl-semantics/direct#owl_maxCardinality_semantics) > the description should then say "... i, j, k such that i+j =< k. In this > example, they are chosen as 2, 3 and 4." > I have looked at the test and believe it to be valid non-entailment. Consider an interpretation that has denotes A with a class with extension { a1, a2 } B .... ..... { b1, b2, b3 } and a further individual i, where these six individuals are distinct and p is a property with extension < i a1 >, < i a2 > q is a property with extension < i b1 > < i b2 > < i b3 > and r is the union of p and q. then i is in (at-least 2 p) i is in (at-least 3 q) but i is not in (at-least 6 r) showing that the intersectionOf (at-least 2 p) and (at-least 3 q) is not a subclassof (at-least 6 r) I think this is a syntactic misunderstanding. Please send me a URL for your syntax and I will try and speak your language a bit better. If you will be in Budapest next week please look me up (I am staying in the main conference hotel) > The same is to <description-logic/Manifest904#test>. > > BTW: the current tests are not very sophisticated. I suggest > to add more complex cardinality test. > > E.g. the following entailments: > > (define-primitive-concept conclusion-x1 > (and (at-least 2 p) > (at-most 2 q) > (exactly 3 r))) > > (define-primitive-concept conclusion-x2 > (and (at-most 2 p) > (at-least 4 r) > (at-most 2 q))) > > (define-primitive-concept conclusion-x3 > (and (at-most 2 p) > (at-least 4 r) > (all r A) > (at-least 3 q))) > > Or even more complex: > > (define-primitive-concept C) > (define-primitive-concept A C) > (define-primitive-concept B (and C (not A))) > (define-primitive-concept D C) > (define-primitive-role r :range C) > (define-primitive-role p :parent r :range A) > (define-primitive-role q :parent r :range B) > (define-primitive-role s :parent r :range D) > > (define-primitive-concept conclusion-x4 > (and (exactly 3 p) > (exactly 3 q) > (exactly 3 s) > (at-most 6 r))) > > And some corresponding non-entailments. > > Thorsten >

Received on Friday, 16 May 2003 12:00:28 UTC