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This entry is from Winter semester 2022/23 and might be obsolete. No current equivalent could be found.

CS 625 — Descriptional Complexity
(dt. Beschreibungskomplexität)

Level, degree of commitment Specialization module, depends on importing study program
Forms of teaching and learning,
Lecture (4 SWS), recitation class (2 SWS),
270 hours (90 h attendance, 180 h private study)
Credit points,
formal requirements
6 CP
Course requirement(s): Successful completion of at least 50 percent of the points from the weekly exercises as well as at least 2 presentations of the tasks.
Examination type: Oral or written examination
The grading is done with 0 to 15 points according to the examination regulations for the degree program M.Sc. Computer Science.
Subject, Origin Computer Science, M.Sc. Computer Science
One semester,
Person in charge of the module's outline Prof. Dr. Detlef Wotschke


The great Greek philosopher Socrates is often quoted - in short form - as follows: I know I don't know anything! This statement, which in essence is still true in many cases, is easily forgotten in today's information and knowledge society and is not very practicable, at least for a computer scientist. But it is still true that we have generally only understood a fact, an object or a process reasonably correctly or well if we can model or describe these things relatively easily or understandably. In almost all areas of computer science, for example, efforts are made to create ''appropriately'' simple or understandable models or descriptions.

In the course announced, the descriptive complexity of formal languages and automata will be examined. Using different measures (e.g. length of description, number of states, non-terminals, productions), the extent to which different description techniques or description resources (e.g. vending machines, grammars, non-determinism, ambiguity) enable considerably shorter or simpler representations is investigated.

In particular, this question is investigated for stochastic, non-deterministic, unambiguous and deterministic finite automata, as well as for context-free grammars and cellar automata, where even reductions of description complexity may occur, which are not limited by any recursive function.

Qualification Goals

Understanding and mastering the learning material for descriptive complexity, training oral communication skills in the exercises by practicing free speech in front of an audience and during discussion.


None. The competences taught in the following module are recommended: Theoretical Computer Science.

Recommended Reading

  • Übersichtsartikel:
  • Jonathan Goldstine, Martin Kappes, Chandra M. R. Kintala, Hing Leung, Andreas Malcher, and Detlef Wotschke. Descriptional complexity of machines with limited resources. J.UCS, 8(2):193 - 234, 2002.

Please note:

This page describes a module according to the latest valid module guide in Winter semester 2022/23. Most rules valid for a module are not covered by the examination regulations and can therefore be updated on a semesterly basis. The following versions are available in the online module guide:

The module guide contains all modules, independent of the current event offer. Please compare the current course catalogue in Marvin.

The information in this online module guide was created automatically. Legally binding is only the information in the examination regulations (Prüfungsordnung). If you notice any discrepancies or errors, we would be grateful for any advice.