Faculty of Computer Science Institute of Theoretical Computer Science, Chair of Automata Theory
Description Logic
Winter Semester 2017/18Exercise Sheet 9 13th December 2017
Prof. Dr.-Ing. Franz Baader, Dr.-Ing. Stefan Borgwardt
Exercise 9.1 Determine whether Player1has a winning strategy in the following finite Boolean games, where in both casesΓ1={p1,p3}andΓ2={p2,p4}:
(a) ((p1∧p3)→ ¬p2)∧(¬p1→ p1)∧(¬p2→(p3∨p4))
(b) (p1∨ ¬p2)∧(p2∨p3)∧(¬p3∨ ¬p4)∧(¬p1∨ ¬p2∨p3∨p4)
Exercise 9.2 Use theALC-Elimalgorithm to decide satisfiability of (a) the concept nameAw.r.t.T ={Av ∃r.A, > vA, ∀r.Av ∃r.A}. (b) the concept∀r.∀r.¬Bw.r.t.T ={¬AvB, Av ¬B, > v ¬∀r.A}.
Give the constructed type sequenceΓ0,Γ1, . . .. In case of satisfiability, also give the satisfying model constructed in the proof of Lemma 5.10.
Exercise 9.3 Extend theALC-Elimalgorithm to the description logicALCI. Prove the correctness of the extended algorithm.
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