Description Logic

PD Dr.-Ing. habil. Anni-Yasmin Turhan


Course Description

Description Logics (DLs) are a successful family of logic-based knowledge representation formalisms which can be used to represent the conceptual knowledge of an application domain in a structured and formally well-understood way. They are employed in various application domains such as natural language processing, configuration, and databases, but their most notable success so far is the adoption of the DL-based language OWL as standard ontology language for the semantic web. This course concentrates on designing and analysing reasoning procedures for DLs. After a short introduction of predecessor formalisms like semantic networks and frames, it will introduce the basic features of DLs, e.g., concepts, TBoxes, and ABoxes, and basic inference problems such as the subsumption and the instance problem. The course introduces techniques for solving these problems based on tableaux algorithms, automata, and other approaches. Also, the complexity of standard DLs is analysed, identifying expressive DLs for which reasoning is expensive in the worst case, but still manageable in practice, and lightweight DLs for which reasoning is tractable.

Organisation

The lecture takes place twice a week. Additionally, there is a weekly exercise session held by Dipl.-Math. Francesco Kriegel. Exercise sheets will be available approximately one week before the session.

The lectures and the exercise sessions will take place in room E005 at the following times: Tuesdays 16.40–18.10, Wednesdays 14.50–16.20, and Thursdays 16.40–18.10. The exact distribution of lectures and exercise sessions can be found in the table below.

Announcements:
Tuesday Wednesday Thursday
12 Oct. to 16 Oct. Lecture Lecture Lecture
19 Oct. to 23 Oct. Lecture Exercise session
(exercise sheet 1)
Lecture
26 Oct. to 30 Oct. Lecture Exercise session
(exercise sheet 2)
Lecture
2 Nov. to 6 Nov. Lecture Exercise session
(exercise sheet 3)
Lecture
9 Nov. to 13 Nov. Lecture Exercise session
(exercise sheet 4)
Lecture
16 Nov. to 20 Nov. Exercise session
(exercise sheet 5)
Public holiday Lecture
23 Nov. to 27 Nov. Lecture Exercise session
(exercise sheet 6)
Lecture
30 Nov. to 4 Dec. Lecture Exercise session
(exercise sheet 7)
Lecture
7 Dec. to 11 Dec. Lecture Exercise session
(exercise sheet 8)
Lecture
14 Dec. to 18 Dec. Lecture Exercise session
(exercise sheet 9)
Lecture
4 Jan. to 8 Jan. Lecture Exercise session
(exercise sheet 10)
Lecture
11 Jan. to 15 Jan. Lecture Exercise session
(exercise sheet 11)
Lecture
18 Jan. to 22 Jan. Lecture Exercise session
(exercise sheet 12)
Lecture
25 Jan. to 29 Jan. Lecture Exercise session
(exercise sheet 13)
Lecture
1 Feb. to 5 Feb. Lecture Exercise session
(exercise sheet 14)
Lecture

SWS/Modules

SWS: 4/2/–

This course can be used in the following modules:

Lecture Material

A script of this lecture is not available, and students are strongly recommended to copy what is written on the blackboard.

We provide, however, the slides for the introductory sessions: Also, we provide scanned versions of the example slides used in the session about frames and semantic networks:

Literature