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 2005

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 .

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

Previous years (course T-79.148): [Spring 2005] [Autumn 2004] [Spring 2004] [Autumn 2003] [Spring 2003] [Autumn 2002] [Spring 2002] [Spring 2001] [Spring 2000] [Spring 1999] [Spring 1998]


  • The departmental course feedback questionnaires for courses in autumn 2005 are accessible here from Fri 9 Dec until Mon 2 Jan. Please reply; you will earn yet another bonus point (cf. below).
  • The final exam for the course takes place on Wed 14 Dec. Registration for the exam is open in TOPI until Fri 9 Dec, 6 p.m.
  • As a general requirement, all compulsory Regis assignments must have been completed before participating in any exam of the course. Exam papers for students with outstanding Regis assignments will not be graded. Really!
  • Recommended reading for Finnish students: Ajankäyttötutkimuksen satoa eli miten saan ystäviä, menestystä ja hyvän arvosanan tietojenkäsittelyteorian perusteista by Harri Haanpää (a statistical analysis of factors affecting course performance in Spring 2004, in Finnish).

General Information

  • The course consists of:
    • lectures (2 h per week, in Finnish)
    • tutorials (1 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 Mon 12 Sep at 9:00 and closes Fri 23 Sep at 16:00.

  • 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 Pekka Orponen on Thursdays 2 p.m. - 4 p.m. in Lecture Hall T1 of the Computer Science building. The first lecture is on Thu 15 Sep. The lectures are in Finnish, and the slides will appear here after each lecture. The contents will likely be very close to those of course T-79.148 in previous years, e.g. Spring 2005.

English translations of the lecture slides from Spring 2004 are available here.

Lecture schedule (tentative):
Week Date Topic Sipser Lewis-Papadimitriou Lecture slides (in Finnish)
37.Sep 15 Review of basic mathematics (functions, relations, induction). Pp. 1-13, 23-25 1.1-1.3, 1.5 PostScript PDF
38.Sep 22 Alphabets, strings and languages. Finite automata. Pp. 13-14, 16, 31-43 1.7, 2.1 PostScript PDF
39.Sep 29 Automata minimisation. Nondeterministic finite automata. Pp. 47-58, 275 2.2, 2.5 PostScript PDF
40.Oct 6 Regular expressions and finite automata. Pp. 58-76 1.8, 2.3 PostScript PDF
41.Oct 13 Context-free grammars and languages. Parse trees and derivations. Pp. 91-98 3.1, 3.2 PostScript PDF
42.Oct 20 Regular grammars. Recursive-descent parsing of LL(1) grammars. - 3.1.5, 3.7 (partly) PostScript PDF
43.Oct 27 Exam week
44.Nov 3 Chomsky normal form and the CYK parsing algorithm. Pushdown automata. Pp. 98-114, 240-241 3.3, 3.4, 3.6 PostScript PDF
45.Nov 10 Regular and context-free pumping lemmata. Countable and uncountable sets. The halting problem. Pp. 77-83, 115-119, 161-164 1.4, 2.4, 3.5 PostScript PDF
46.Nov 17 Turing machines: standard, multitrack and multitape. Nondeterministic Turing machines. Pp. 125-140 4.1, 4.3, 4.5 PostScript PDF
47.Nov 24 Recursive and recursively enumerable languages. Turing machine encoding and universal Turing machines. 142-143, 4.2, 5.1, 5.2, 5.7 PostScript PDF
48.Dec 1 Undecidability. Rice's theorem. 159-168, 171-174, 1965.3, 5.4 PostScript PDF
49.Dec 8 General and context-sensitive grammars. Linear bounded automata. The Chomsky hierarchy. -4.6 p. 271 PostScript PDF


The tutorials start the week after the first lecture. The Tuesday 16-17 tutorial session is given in English, the others are in Finnish. The head assistant of the course is Tommi Syrjänen.

Day Time Location Assistant
Mon 16-18 T4 Vesa Ojala (Advice session: no registration, no credit. First period only.)
Tue 12-13 Y228 Antti Rusanen
13-14 Y228 Antti Rusanen
16-17 Y405 Tommi Syrjänen (In English)
17-18 Y405 Tommi Syrjänen
Wed 12-13 Y313 Antti Hyvärinen
13-14 Y313 Antti Hyvärinen
14-15 U264 Vesa Ojala
15-16 U264 Vesa Ojala

TOPI registration for the tutorials opens Mon 12 Sep at 9:00 and closes Fri 23 Sep at 16:00. 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 (max 6) 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
5 1
10 2
15 3
20 4
25 5
30 6

The demonstration problems are likely to be 90% the same as in the previous instalment of the course T-79.148, 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 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.

  1. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  2. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  3. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  4. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  5. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  6. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  7. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  8. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  9. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  10. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)
  11. tehtävät (pdf) ratkaisut (pdf) problems (pdf) solutions (pdf)

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). As long as that schedule holds:

  • 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. The main course exam in Autumn 2005 is scheduled for Wed 14 December. There is also an exam of the previous version of the course, T-79.148, scheduled for Thu 27 October.

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 max 6 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 4 tutorial bonus points), 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 help to change the exam grade from failing to passing. 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 October 27, 9 a.m.



Please provide feedback on the course via the DCSE department's course feedback system. Filling in the feedback form is rewarded by one bonus exam point, used to increase any passing grade earned from the course. The feedback system will open on Fri 21 Oct and close on Fri 4 Nov.

Summaries of feedback from previous courses: Autumn 2003 Spring 2003 Autumn 2002, Spring 2002.


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

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Latest update: 19 January 2006. Pekka Orponen