
258 Foundations of Semantic Web Technologies
Exercise 6. 7 We have seen that the datalog rule
orderedDish(x, y) ∧ dislikes(x, y) → Unhappy(x)
from Fig. 6.1 is not a Description Logic Rule. Consider the following set of
description logic axioms, where R
Unhappy
is a new role name:
Unhappy ≡ ∃R
Unhappy
.Self
orderedDish ◦ dislikes
−
v R
Unhappy
1. Explain why this set of axioms can be used to simulate the above rule
under the usual description logic semantics.
2. Why is it not possible to use this translation in SROIQ? (Hint: Review
the syntactic restrictions explained in Section 5.1.4.)
6.7 Further Reading
A comprehensive textbook reference for datalog is [AHV94]. ...