Course details

# Theoretical Computer Science

TIN Acad. year 2021/2022 Winter semester 7 credits

An overview of the applications of the formal language theory in modern computer science and engineering (compilers, system modelling and analysis, linguistics, etc.), the modelling and decision power of formalisms, regular languages and their properties, minimalization of finite-state automata, context-free languages and their properties, Turing machines, properties of recursively enumerable and recursive languages, computable functions, undecidability, undecidable problems of the formal language theory, and the introduction to complexity theory.

Guarantor

Course coordinator

Language of instruction

Completion

Time span

- 39 hrs lectures
- 26 hrs exercises
- 13 hrs projects

Assessment points

- 60 pts final exam (written part)
- 25 pts mid-term test (written part)
- 15 pts projects

Department

Lecturer

Instructor

Duránik Lukáš (DFIT-En)

Holík Lukáš, doc. Mgr., Ph.D. (DITS)

Lengál Ondřej, Ing., Ph.D. (DITS)

Rogalewicz Adam, doc. Mgr., Ph.D. (DITS)

Vojnar Tomáš, prof. Ing., Ph.D. (DITS)

Course Web Pages

Subject specific learning outcomes and competences

The students are acquainted with basic as well as more advanced terms, approaches, and results of the theory of automata and formal languages and with basics of the theory of computability and complexity allowing them to better understand the nature of the various ways of describing and implementing computer-aided systems.

The students acquire basic capabilities for theoretical research activities.

Learning objectives

To acquaint students with more advanced parts of the formal language theory, with basics of the theory of computability, and with basic terms of the complexity theory.

Why is the course taught

The course acquaints students with fundamental principles of computer science and allows them to understand where boundaries of computability lie, what the costs of solving various problems on computers are, and hence where there are limits of what one can expect from solving problems on computing devices - at least those currently known. Further, the course acquaints students, much more deeply than in the bachelor studies, with a number of concrete concepts, such as various kinds of automata and grammars, and concrete algorithms over them, which are commonly used in many application areas (e.g., compilers, text processing, network traffic analysis, optimisation of both hardware and software, modelling and design of computer systems, static and dynamic analysis and verification, artificial intelligence, etc.). Deeper knowledge of this area will allow the students to not only apply existing algorithms but to also extend them and/or to adjust them to fit the exact needs of the concrete problem being solved as often needed in practice. Finally, the course builds the students capabilities of abstract and systematic thinking, abilities to read and understand formal texts (hence allowing them to understand and apply in practice continuously appearing new research results), as well as abilities of exact communication of their ideas.

Prerequisite knowledge and skills

Basic knowledge of discrete mathematics concepts including algebra, mathematical logic, graph theory and formal languages concepts, and basic concepts of algorithmic complexity.

Study literature

- Češka, M. a kol.: Vyčíslitelnost a složitost, Nakl. VUT Brno, 1993. ISBN 80-214-0441-8
- Češka, M., Rábová, Z.: Gramatiky a jazyky, Nakl. VUT Brno, 1992. ISBN 80-214-0449-3
- Češka, M., Vojnar, T.: Studijní text k předmětu Teoretická informatika (http://www.fit.vutbr.cz/study/courses/TIN/public/Texty/TIN-studijni-text.pdf), 165 str. (in Czech)
- Kozen, D.C.: Automata and Computability, Springer-Verlag, New Yourk, Inc, 1997. ISBN 0-387-94907-0
- Hopcroft, J.E., Motwani, R., Ullman, J.D.: Introduction to Automata Theory, Languages, and Computation, Addison Wesley, 2nd ed., 2000. ISBN 0-201-44124-1
- Meduna, A.: Formal Languages and Computation. New York, Taylor & Francis, 2014.
- Aho, A.V., Ullmann, J.D.: The Theory of Parsing,Translation and Compiling, Prentice-Hall, 1972. ISBN 0-139-14564-8
- Martin, J.C.: Introduction to Languages and the Theory of Computation, McGraw-Hill, Inc., 3rd ed., 2002. ISBN 0-072-32200-4
- Brookshear, J.G. : Theory of Computation: Formal Languages, Automata, and Complexity, The Benjamin/Cummings Publishing Company, Inc, Redwood City, California, 1989. ISBN 0-805-30143-7

Fundamental literature

- Hopcroft, J.E., Motwani, R., Ullman, J.D.: Introduction to Automata Theory, Languages, and Computation, Addison Wesley, 2nd ed., 2000. ISBN 0-201-44124-1
- Kozen, D.C.: Automata and Computability, Springer-Verlag, New Yourk, Inc, 1997. ISBN 0-387-94907-0
- Martin, J.C.: Introduction to Languages and the Theory of Computation, McGraw-Hill, Inc., 3rd ed., 2002. ISBN 0-072-32200-4
- Brookshear, J.G. : Theory of Computation: Formal Languages, Automata, and Complexity, The Benjamin/Cummings Publishing Company, Inc, Redwood City, California, 1989. ISBN 0-805-30143-7
- Aho, A.V., Ullmann, J.D.: The Theory of Parsing,Translation and Compiling, Prentice-Hall, 1972. ISBN 0-139-14564-8

Syllabus of lectures

- An introduction to the theory of formal languages, regular languages and grammars, finite automata, regular expressions.
- Minimization of finite-state automata, pumping theorem, Nerod's theorem, decidable problems of regular languages.
- Context-free languages and grammars, push-down automata, transformations and normal forms of context-free grammars.
- Advanced properties of context-free languages, pumping theorem for context-free languages, decidable problems of context-free languages, deterministic context-free languages.
- Turing machines (TMs), the language accepted by a TM, recursively enumerable and recursive languages and problems.
- TMs with more tapes, nondeterministic TMs, universal TMs.
- The relation of TMs and computable functions.
- TMs and type-0 languages, diagonalization, properties of recursively enumerable and recursive languages, linearly bounded automata and type-1 languages.
- The Church-Turing thesis, undecidability, the halting problem, reductions, Post's correspondence problem, undecidable problems of the formal language theory.
- Gödel's incompleteness theorems.
- An introduction to the computational complexity, Turing complexity, asymptotic complexity.
- P and NP classes and beyond, polynomial reduction, completeness.

Syllabus of numerical exercises

- Formal languages, and operations over them. Grammars, the Chomsky hierarchy of grammars and languages.
- Regular languages and finite-state automata (FSA) and their determinization.
- Conversion of regular expressions to FSA. Minimization of FSA. Pumping lemma
- Context-free languages and grammars. Transformations of context-free grammars.
- Operations on context-free languages and their closure properties. Pumping lemma for context-free languages.
- Push-down automata, (nondeterministic) top-down and bottom-up syntax analysis. Deterministic push-down languages.
- Turing machines.
- Turing machines and computable functions.
- Recursive and recursively enumerable languages and their properties.
- Decidability, semi-decidability, and undecidability of problems, reductions of problems.
- Complexity classes. Properties of space and time complexity classes.
- P and NP problems. Polynomial reduction.

Syllabus - others, projects and individual work of students

- Assignment in the area of regular and context free languages.
- Assignment in the area of Turing machines and the theory of undecidability.
- Assignment in the area of computable functions and complexity.

Progress assessment

An evaluation of the exam in the 5th week (max. 15 points) and in the 10th week (max. 15 points), an evaluation of the assignments (max 3-times 5 points) and an final exam evaluation (max 60 points).

Controlled instruction

A written exam in the 4th week focusing on the fundamental as well as on advance topics in the area of regular languages. A written exam in the 9th week focusing on advance topics in the area of context-free languages, and on Turing machines, regular evaluation of the assignments, a final written exam. **Students have to achieve at least 25 points, otherwise the exam is assessed by 0 points.**

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Exam prerequisites

The minimal total score of 15 points achieved from the first two assignments, and from the exams in the 5th and 10th week (i.e. out of 35 points).

Course inclusion in study plans