TCS / Studies / T-79.1001 Introduction to Theoretical Computer Science T
Helsinki University of Technology, 
     Laboratory for Theoretical Computer Science

T-79.1001 Introduction to Theoretical Computer Science T (4 cr)

Autumn 2006

This introductory course on the theory of computation covers the basic aspects of finite automata and regular languages, context-free grammars and pushdown automata, Turing machines and computability theory.

The course T-79.1001 replaces the earlier course T-79.148 Introduction to Theoretical Computer Science .

Starting in 2006/07, the course is lectured in the autumn semester only.

[Current] [General] [Lectures] [Tutorials] [Exams] [Material] [Feedback] [Links]

Previous years: [Spring 2006] [Autumn 2005] [Spring 2005] [Autumn 2004] [Spring 2004] [Autumn 2003] [Spring 2003] [Autumn 2002] [Spring 2002] [Spring 2001] [Spring 2000] [Spring 1999] [Spring 1998]


General Information

  • The course consists of:
    • lectures (2 h per week, in Finnish)
    • tutorials (2 h per week, one group in English)
    • an examination

  • Registration for the course is by TOPI. You must register in order to take the course, even if you were not intending to attend the lectures or the tutorials. (Registrations are needed for bookkeeping purposes, specifically for generating your set of computerised home assignments; see below.) One of the tutorial groups (indicated below) will be given in English and the rest in Finnish. Registration for the tutorials opens Sep 1 at 9:00 and closes 28 Sep at 18:00.

  • In order to pass the course you have to:
    1. complete four compulsory sets of home assignments, and
    2. get a passing grade on the exam, as augmented by credit earned from the tutorials.
    The compulsory assignments are individually computer-generated for each student, and are submitted over the network. Completing these assignments is a mandatory prerequisite for participating in the exam. For more details, see the computerised assignments info page.

  • Newsgroup: opinnot.tik.tkt


Lectures by Harri Haanpää on Thursdays 2 p.m. - 4 p.m. in Lecture Hall T1 of the Computer Science building. The first lecture is on Thu 14 Sep. The lectures are in Finnish, and the slides will appear here after each lecture. The contents will likely be very close to those from previous years, e.g. Spring 2006.

Lecture schedule (tentative):
Date Topic Sipser Lewis-Papadimitriou
Sep 14
Review of basic mathematics (functions, relations, induction). Alphabets, strings and languages. Pp. 1-16, 23-25 1.1-1.3, 1.5, 1.7
Sep 21
Finite automata. Pp. 31-43 2.1
Sep 28
Automata minimisation. Nondeterministic finite automata. Pp. 47-58, 275 2.2, 2.5
Oct 5
Regular expressions and finite automata. Pp. 58-76 1.8, 2.3
Oct 12
Context-free grammars and languages. Regular grammars. Pp. 91-98 3.1
Oct 19
Parse trees and derivations. Recursive-descent parsing of LL(1) grammars. - 3.2, 3.7 (partly)

Oct 26
Exam week; no lecture.
Nov 2
Chomsky normal form and the CYK parsing algorithm. Pushdown automata. Pp. 98-114, 240-241 3.3, 3.4, 3.6
Nov 9
Countable and uncountable sets. The halting problem. Regular and context-free pumping lemmata. Pp. 77-83, 115-119, 161-164 1.4, 2.4, 3.5
Nov 16
Turing machines: standard, multitrack and multitape. Nondeterministic Turing machines. Pp. 125-140 4.1, 4.3, 4.5
10 Nov 23
Recursive and recursively enumerable languages. Turing machine encoding and universal Turing machines. 142-143, 4.2, 5.1, 5.2, 5.7
11 Nov 30
Undecidability. Rice's theorem. 159-168, 171-174, 196 5.3, 5.4
12 Dec 7
General and context-sensitive grammars. Linear bounded automata. The Chomsky hierarchy. - 4.6 p. 271
13 N/A
Review and discussion of the course material. Exam requirements.


The tutorials start the week after the first lecture. The Tuesday 16-18 tutorial session is given in English, the others are in Finnish. The head assistant of the course is Tommi Syrjänen.

Day Time Location Assistant
12-14 U358
Emilia Oikarinen
(In period I only)

14-16 U358
Tommi Syrjänen
(In period I only)
12-14 Y228 Tuomas Launiainen

16-18 Y405 Tommi Syrjänen (In English)
Wed 12-14 Y313 Petri Savola

14-16 U264 Emilia Oikarinen

TOPI registration for the tutorials opens Friday 1 September at 9:00 and closes Thursday 28 September at 18:00. You must register in order to take the course, even if you were not intending to physically attend the tutorials. (Registrations are needed for bookkeeping purposes, specifically for generating your set of computerised home assignments; see below.)

In the tutorials, there will be three home assignments and two or three demonstration problems each week. The tutorials are not compulsory, but bonus exam points (-2 to 4) will be awarded for doing the home assignments and marking them as done at the tutorial sessions. The grading scheme for the home assignments is as follows:
Problems solved Bonus points on T course Bonus points on Y course
5-9 -1
10-14 0
15-19 1
20-24 2
25-29 3
30- 4

The demonstration problems are likely to be 90% the same as in the previous instalment of the course, and are discussed at the tutorials to the extent that time permits. In addition to the voluntary tutorials there are three compulsory computer-generated "Regis" problem sets. (See the info page.)

Tutorial problems: Electronic copies (in PDF) downloadable here each week. Paper copies available at the lectures, and from the rack outside the theory lab office (TB336). Solutions for the demonstration problems are provided here as the course progresses.

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Tutorial scores.

Validity of tutorial and Regis problems and their bonus points. Exams for the course are for the time being scheduled for examination periods 1, 2, 3, 5 and 6 of the academic year (August, October, December, March, May).

  • The Regis problems generated in a given autumn / spring semester will be valid until the Mar / Oct exam in the following semester.
  • Fully completed Regis assignments, and any bonus points earned in a given autumn / spring semester will be valid until the Oct / Mar exam in the following year.

Examinations and Grading

In general, exams for the course are scheduled for March, May, August, October, and December of each year. In 2006/07 exams are scheduled for 30 Aug, 26 Oct, 21 Dec, 6 Mar and 10 May. The December exam is the main exam for T-79.1001 and the October exam is the main exam for T-79.1002.

To participate in an exam, you must first complete your personal computer-aided Regis exercises. See the exam requirements. Remember also to register for the exam.

Grading: Exam max 60 points, tutorials -2...4 points. Min passing grade approx. 30 points (tolerance 4 p), highest grade (5) approx. 54 points. In the case of "close call" failures (at most 2 points below passing) despite serious study effort (at least half of the tutorial exercises done), there is a possibility of getting a passing grade by solving additional tutorial problems. To discuss this option, please contact the lecturer after the exam has been graded.

Bonus points earned from the tutorials are added directly to the exam points, and may change the exam grade from failing to passing or vice versa. Bonus points earned from Regis/Stratum assignments completed on time (see the info page) are only added afterwards to a passing exam grade, and may thus help to increase the grade, but not pass the course. Note that the Regis assignments must in any case be completed before the exam, and extra points are awarded only for completion by the bonus deadline of Oct 26 1 p.m.


  • Lecture Notes: Typeset lecture notes (in Finnish) distributed by Edita.
  • Textbook(s): The recommended English textbook for the course is M. Sipser, Introduction to the Theory of Computation (PWS Publishing 1997). Finnish students do not need to purchase the textbook, since the course follows closely the lecture notes. However the Sipser book is very reader-friendly yet insightful, so reading it on the side will help in following the course. The former recommended text, H. Lewis and C. Papadimitriou, Elements of the Theory of Computation (Prentice Hall 1998) is being phased out. 
  • Supporting material:
    • Demonstration problems and their solutions from the tutorials will be provided with the lecture notes; updates available as the course progresses.
    • Some of the material will be available also via this web page. Please avoid unnecessary printing of this material to save printers, paper and thus nature !!!
    • A short introduction to set theory and relations (by Tommi Syrjänen, in Finnish, ps/ pdf).
    • An example on determinising a finite-state automaton (by Heikki Tauriainen, in Finnish, ps/ pdf.
    • An introduction to pumping lemmata and their uses (by Tommi Syrjänen, in Finnish, ps/ pdf.
    • Solutions for one old examination (25.10.2003), in Finnish, ps/ pdf.

  • Examination requirements are available.
  • Previous exams of the T-79.1001 course
  • Previous exams of the old T-79.148 course


Please provide feedback on the course via the DCSE department's course feedback system. at the end of the course.


Some useful and fun links that are related to the course contents, but not part of the official course material.

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Latest update: 09 February 2007. Harri Haanpää