Calendari del curs 2025/2026 Q2

Grupo 11
Dt 10–12 (A6106)
Ilario Bonacina
Dc 10–12 (A5S109)
David Garcia Soriano
Grupo 12
Dt 12–14 (A6105)
Enrique Romero
Dc 8–10 (A5S111)
Enrique Romero
Grupo 21
Dt 16–18 (A6101)
Antoni Lozano
Dc 15–17 (A5S102)
Antoni Lozano
Setmana Data Tema de la classe
1

10/02/2025

Overview of the course, administrative part. Introduction (math background, formal languages, proofs techniques).
Solution of some exercises from Problem Set 0 (in groups in class).

11/02/2025

Regular languages (DFAs, \lambda-NFAs, examples, cartesian product and some closure properties).
Construction of DFAs using RACSO.

2

17/02/2025

Proof techniques: contradiction, cases, induction, pigeonhole principle, diagonalization.
Solution of some exercises from Problem Set 0 (in groups in class).

18/02/2025

Determinization (subset set construction). Closure under concatenation and Kleene star.
Construction of DFAs using RACSO.

3

24/02/2025

Minimization of DFAs (Moore’s algorithm).
Students presentations of exercises from Problem Set 1.

Homework 1 is due on this class (see the racó for the exercise from Problem Set 1 assigned to you)

25/02/2025

Regular expressions and equivalence with DFAs (Arden’s Lemma). Examples.
Construction of DFAs using RACSO.

4

03/03/2025

\{a^n b^n \mid n\in \mathbb N\} is not regular. Pumping Lemma for regular languages. Proofs of non regularity through closure properties.
Students presentations of exercises from Problem Set 1

04/03/2025

Context-Free Grammars, parse trees, ambiguity. Closure properties of CFGs. Regulars are included in CFL.
Construction of CFGs using RACSO.

5

10/03/2025

Depuration of CFGs. Chomsky Normal Form.
Students presentations of exercises from Problem Set 1.

11/03/2025

Cocke-Younger-Kasami parsing algorithm.
Construction of CFGs using RACSO.

6

17/03/2025

\{a^n b^n c^n \mid n\in \mathbb N\} is not context-free. Pumping Lemma for CFL. Non context-freeness using closure operations.
Students presentations of exercises from Problem Set 2.

Homework 2 is due on this class (see the racó for the exercise from Problem Set 2 assigned to you)

18/03/2025

Push-down automata. Equivalence with CFGs.
Construction of CFGs using RACSO.

7

24/03/2025

Closure of CFL under intersection with regular languages and inverse homomorphism.
Students presentations of exercises from Problem Set 2.

25/03/2025

Students presentations of exercises from Problem Set 2.
Past exam exercsies on RACSO.

08/04/2026 Midterm 1
8

14/04/2025

Turing Machines: basic properties, Church-Turing Thesis, Gödel numbering, Universal TM.

15/04/2025

Definition of \mathbf{R} (decidable languages), \mathbf{RE} (semi-decidable languages), and \mathbf{coRE}. Undecidability of \mathtt{K} (\mathtt{K}\notin \mathbf{R}).
Construction of PDAs using RACSO.

9

21/04/2025

\mathbf{RE} \cap \mathbf{coRE} = \mathbf{R}. Projection theorem for \mathbf{RE} (and analogue for \mathbf{coRE}).
Students presentations of exercises from Problem Set 3.

Homework 3 is due on this class (see the racó for the exercise from Problem Set 3 assigned to you)

22/04/2025

Many-one reductions. Proving undecidability through reductions. Examples.
Construction of PDAs using RACSO.

10

28/04/2025

Undecidable properties of CFGs (statements only). Arithmetic hierarchy.
Students presentations of exercises from Problem Set 3.

29/04/2025

Recap of \mathbf{P}, \mathbf{NP}, \mathbf{coNP}, \mathbf{EXP}.
Construction of PDAs using RACSO.

11

05/05/2025

\mathbf{NP}-completeness and polynomial-time reductions.
Students presentations of exercises from Problem Set 3.

06/05/2025

Cook-Levin Theorem. Reductions from \mathtt{SAT}.
Construction of reductions from \mathtt{K} using RACSO.

12

12/05/2025

More reductions from \mathtt{SAT}.
Students presentations of exercises from Problem Set 4.

Homework 4 is due on this class (see the racó for the exercise from Problem Set 4 assigned to you)

13/05/2025

\mathbf{NP}-intermediate problems (factoring, graph isomorphism, discrete log). Ladner’s Theorem.
Construction of reductions from \mathtt{K} using RACSO.

13

19/05/2025

Time-constructible functions. Time-hierarchy theorem. \mathbf{P}\neq \mathbf{EXP}.
Students presentations of exercises from Problem Set 4.

20/05/2025

Classes \Sigma^P_2 and \Pi^P_2. The Polynomial Hierarchy (via quantifiers). Properties.
Construction of reductions from \mathtt{K} using RACSO.

14

26/05/2025

Definition of the PH via oracle machines. Turing reductions.
Students presentations of exercises from Problem Set 4.

27/05/2025

Relativization of \mathbf{P} = \mathbf{NP}: the limits of diagonalization.
Past exam exercsies on RACSO.

05/06/2026 Midterm 2
15/06/2026 Final exam