Faculty of Computer Science Institute of Theoretical Computer Science, Chair of Automata Theory
Description Logic
Winter Semester 2017/18Exercise Sheet 11 10th January 2018
Prof. Dr.-Ing. Franz Baader, Dr.-Ing. Stefan Borgwardt
Exercise 11.1 LetT1be anEL-TBox,C,DEL-concepts, andT2 =T1∪ {AvC, Dv B}, where A,Bare new concept names (as in Lemma 6.1). Show thatT2is a conservative extension ofT1. Is this still the case after addingAvBtoT2? What about addingBv A?
Exercise 11.2 Consider the TBox
T ={AvBu ∃r.C, Bu ∃r.BvCuD, Cv(∃r.A)uB, (∃r.∃r.B)uDv ∃r.(AuB)},
whereA,B,C,Dare concept names. Use the classification procedure forELto check whether the following subsumption relationships hold w.r.t.T:
(a) AvB (b) Av ∃r.∃r.A (c) Bu ∃r.Av ∃r.C
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