1. Dr. Jim Bowring Computer Science Department College of Charleston CSIS 690 (633) May Evening 2009 Semantic Web Principles and Practice Class 12: 22 June 2009

2. Class 12: Roadmap Announcements and Assignments Questions SWWO Chapter 10 Begin Student Project Presentations

3. Counting and Sets in OWL Cardinalities the count of distinct values for a property cardinality inferencing

4. Unions and Intersections U1 a owl:Class; owl:unionOf ( ns:A ns:B … ). I1 a owl:Class; owl:intersectionOf ( ns:A ns:B … ). - can use as anonymous classes: “[ ]” - See Example High-Priority Candidate Questions

5. Closing the World How can we guarantee set membership in the presence of the open world assumption? Enumeration with owl:one of ss:SolarPlanet a owl:Class; owl:one of ( ss:Mercury ss:Venus ss:Earth ). Infer: ss:Mercury a ss:SolarPlanet etc.

6. Differentiation owl:differentFrom [ a owl:AllDifferent; owl:distinctMembers ( ss:Mercury ss:Venus ss:Earth ) ].

7. Cardinality [ a owl:Restriction; owl:onProperty :hasPlayer; owl:cardinality 9 ] Or: owl:minCardinality owl:maxCardinality See Challenge 29 and Challenge 30

8. Small Cardinality Limits minCardinality 1 : at least 1 maxCardinality 1 : unique but not required to exist minCardinality 0 : optional maxCardinality 0 : not allowed

9. Set Complement bb:MinorLeaguePlayer owl:complementOf bb:MajorLeaguePlayer. Meaning ? bb:MinorLeaguePlayer owl:intersectionOf ( [ a owl:Class ; owl:complementOf bb:MajorLeaguePlayer] bb:Player ). See Challenge 31

10. Disjoint Sets owl:disjointWith can then infer that individuals owl:differntFrom See Challenge 32

11. Prerequisites Again From chapter 9: q:hasPrerequisites a owl:ObjectPropoerty. [ a owl:Restriction ; owl:onProperty hasPrerrequisite; owl:allValuesFrom q:SelectedAnswer ] rdfs:subClassOf q:EnabledQuestion.

12. No Prerequisites c:WhatProblem a [ a owl:Restriction ; owl:onProperty q:hasPrerequisite ; owl:cardinality 0 ]. infer that there are no triples of the form c:WhatProblem q:hasPrerequisite ?. infer c:WhhatProblem a q:EnabledQuestion. See “Childless parents have all boy children…”

13. Counting Prerequisites TvSymptom a [ owl:Restriction ; owl:onProperty hasPrerequsite ; owl:cardinality 1 ]. Note: owl:someValuesFrom guarantees existence but owl:allValuesFrom does not

14. Contradictions & Unsatisfiable Classes See challenge 33 See pg 240 for further discussion of SW vs OO the end !