Automata Theory

News

• Proseminar talks will take 25 minutes.
  
• We assigned the topics, reviewers, and the dates for the talks.
  
• We fixed the schedule of the talks to the last three sessions in the lecture period, i.e., July 13, 20, and 27.
  
• Please send an email to Christian until Thu, May 11 that contains the following information:
• a list of 3 topics that you want to present (with priorities)
  
• whether you are a seminar or a proseminar student
  
• (optional) if you have time constraints
• (optional) if are an ESE student

Process of the seminar

• You participate in the kick-off meeting, where we present the available topics. Feel free to hand in your favorite topic in advance.
  
• You contact the instructors to obtain a topic. You may suggest a topic by yourself, pick one of the suggested topics, or find a topic suitable for you in a discussion with your supervisor.
• You have a meeting with your supervisor in which we discuss relevant literature and develop a very coarse sketch of your talk (deadline: four weeks before your talk).
• You write a proposal in which you explain what you are going to present in your talk, together with an abstract of your talk. You submit your abstract and your proposal via email to your supervisor (deadline: three weeks before your talk).
  
• Your proposal is reviewed by your supervisor and two other participants.
• You write two reviews about other participants' proposals and send them via email to the supervisor (deadline: one week after you received the proposal).
  
• You receive reviews for your proposal (deadline: two weeks before your talk).
  
• You submit your slides via email to your supervisor (deadline: one week before your talk).
• You have a meeting with your supervisor in which you get feedback for your slides.
  
• You give a talk of 30 minutes (Seminar) / 25 minutes (Proseminar).
  
• You attend the talks of all other participants.

Proposals of the talk

The proposal should consist of around five pages in which you explain what you are going to present in your talk. The proposal may contain:

• short overview for the reviewers (the reviewers will probably not know your topic)
  
• structure of your talk
• aspects of the topic that you present (why?) and ignore (why?)
• examples occurring in the talk (why these examples? Is there a running example that can be used for demonstration?)
  
• which definitions are presented formally? (why?), which definitions are just mentioned informally? (why?)
• which notation is used? (why?)
  
• which theorems are presented, which of them will be proven (why?), which proofs will be omitted (why?), will you use motivating examples in the proof?

Abstract of the talk

• The abstract consists of one paragraph that summarizes what you present in the talk.
• We will send an invitation for the seminar to all students and members of our chair. This invitation contains the abstracts of all talks.

The talk

• The goal of your talk is that the audience (bachelor and master students, familiar with computer science in general, probably no experts in the topic) has the possibility to learn something new about an interesting topic. How well you achieved this goal will determine the grade of your talk.
• In a seminar you have to show that you are able to present some topic to other people. You do not have to show how well you understood the topic for yourself. How well you understood the topic has no direct influence on your grade, but only how well you presented the topic to the audience.
  
• You may use and copy any source of information (but do not forget to cite it). If you think your talk is just a "remix" of existing talks tailored to your audience, you might have done a great job. But do not let yourself be fooled by well-structured and fancy talks found in the web, each talk was prepared to a specific audience.
• If you agree, we will put your slides on this web page. Keep in mind that if you have copied images in your slides this might not be possible anymore (copyright restrictions). Of course, it will not have any effect on your grade whether we may publish your slides or not.
  

Review of the proposal

• Give a short summary of the talk based on the proposal (to detect misunderstandings right at the start).
• Be generous with your criticism. It is very unlikely that a student will get a bad grade because you revealed some problems in his/her proposal. However, it is very likely that a student will get a better grade if he/she was able to resolve a problem in his/her talk, thanks to your review.
  
• Give reasons for your criticism (e.g., "It is not possible to understand Lemma 2 because term foo was not explained.").  You are also allowed to give your personal opinions, if you do so mark them as such (e.g., "Theorem 1 is very difficult to understand, in my opinion you should give an example first.").
• The following questions might be helpful to write your review

Is the proposal sufficiently well written to be readable?
Is the appearance and structure of the proposal appropriate?
Is the comprehensibility of the talk supported by relevant examples and figures?
Is the proposed structure of the talk sensible and balanced?
Are all propositions made by the author correct?
Is the line of reasoning concerning the presentation complete and accurate?
Has the author argued his/her case effectively?
Does the author use the common notation and terminology? Where would you suggest something different?
Is the schedule of the author sensible? Do you think the talk will fit into the time slot?

Grade

Your overall grade will be composed according to the following proportion.

• 10% grade of your proposal
• 20% grade of your reviews
  
• 70% grade of your talk

Topics & literature

There is not a one-to-one correspondence between seminar talks and topics. Several students may give talks on the same topic, but present different aspects. The suggested literature should give you a first impression of the topics. We assign the exact literature in cooperation with you after you stated your preferences for the topic. More literature does not mean more reading, just more options. The order of appearance is arbitrary.

If requested, some topics may also be presented in groups of two.

Some of the papers are only available via the network of our university (e.g., via vpn). If you have some problem accessing the papers, please ask us.

(1) Learning finite automata

• Literature: Learning regular sets from queries and counterexamples, Talk (min. 15-30), Talk (min. 20-34)
• Supervisor: Christian
• Talk: Jacob
• Reviewers: Annette, Paul
  

(1) Symbolic automata

• Literature: Applications of Symbolic Finite Automata, Minimization of symbolic automata
• Supervisor: Christian
• Talk: Paul
• Reviewers: Jacob, Valentin

(2) Petri nets

• Literature: Applied Automata Theory (Chapter 6), Recent and simple algorithms for Petri nets
• Supervisor: Matthias
• Talk: Annette
• Reviewers: Jacob, Valentin

(2) Cellular automata

• Cellular automata (Wikipedia), Game of Life (Wikipedia), Cellular Automata
• Supervisor: Christian
• Talk: Valentin
• Reviewers: Annette, Paul

(3) Efficient representation of finite sets

Not assigned

Büchi automata

• Automata theory - An algorithmic approach (Chapter 11 Section 1-2), Automata on infinite objects (Chapter I Section 1-2)

Tree automata

• Tree automata - Techniques and applications

Parikh's theorem

• Wikipedia, On context-free languages, Proof 1, Proof 2, Proof 3
  

Automata minimization

• Minimal unambiguous epsilon-NFA
• Reduction of nondeterministic tree automata
• Forward bisimulations for nondeterministic symbolic finite automata

Complexity theory

• Minimisation of deterministic parity and Buchi automata and relative minimisation of deterministic finite automata
• P-hardness of the emptiness problem for visibly pushdown languages
• Complete problems for deterministic polynomial time
• PushPush and Push-1 are NP-hard in 2D, Classic Nintendo games are (NP-)hard, Gaming Is a hard job, but someone has to do it!, Playing games with algorithms: algorithmic combinatorial game theory
  
• The hardness of the Lemmings game, or Oh no, more NP-completeness proofs, Computational complexity of two-dimensional platform games, Lemmings is PSPACE-complete
• Computers and intractability - A guide to the theory of NP-completeness (Chapter 7.1)

Antichains

• Wikipedia
• Antichains: A new algorithm for checking universality of finite automata
• Antichain algorithms for finite automata
• When simulation meets antichains

Partial derivatives

• Partial derivatives for context-free languages

Reversible finite automata

• Minimal reversible deterministic finite automata

State complexity

• In search of most complex regular languages

DFA families

• Families of DFAs as acceptors of omega-regular languages

Set automata

• Deterministic set automata [technical report], Regularity and size of set automata, On computational complexity of set automata

mu-Calculus

• Automata, logics, and infinite games (Chapter 10)

Schedule

Each topic/talk has a slot number assigned. We have two slots in total.

The following table contains the deadlines for the groups. Please note that "Review" stands for the review deadline for the specific group's proposals. Each proseminar student has to write reviews for two other students.