The lectures will take place (tentative)

Wednesdays: 11:00 -- 13:00;

Fridays: 9:00 -- 10:00.

Calle Montalegre 6 in Aula 410. However, due to Covid-19 regulations we will be starting with online teaching only, hoping that we may resort to regular teaching shortly. The start date is Wednesday, February 10. Official schedule information can be found here

We observe that our current schedule is slightly different from the original and official one (official is Wednesday from 11:30 -- 12:30 and Fridays 9-11). We decided on this change between all participants.

The final grade is determined by

(A) Homework questions (this may include a mid-term exam); (60 %)

(B) Final Exam; (40 %).

All materials and assignments will also be placed on this page.

Joost J. Joosten is the lecturer of this course. Esperanza Buitrago will be teaching assistant. The best way to contact me is by sending me an e-mail. You can also come around to see if I am in at the Montalegre building in Room 4045 with phone number +34 934037984.

We will have a final exam near the end of the semester. An eventual resit could be held after that. The literature will consist of among others a reader to be distributed among the participants.

The modal logic course constitutes for 5 European credits and as such comprises 42 contact hours, so that makes 14 weeks, 3 hours each. As mentioned, You can find the complete schedule here. Likewise there is an official page with the course description.

Week 1 | | | Week 5 | | | Week 9 | | | Week 13 | |

Week 2 | | | Week 6 | | | Week 10| | | Week 14 | |

Week 3 | | | Week 7 | | | Week 11 | ||

Week 4 | | | Week 8 | | | Week 12 |

We have started our course and dealt with Chapter 1 of the linked document. The homework of this week consists of Exercises 1.6.12, 1.6.16 and 1.6.17. Please hand it in before the next class on Wednesday by sending your solution in pdf to Esperanza.

The homework for this week consists of Exercise 2.4.11 to be handed in before the next lecture on Wednesday in pdf form in a mail to Esperanza.

The homework for over Easter consists of Exercise 5.4.3, 5.4.6, 5.4.9, 5.4.10, and 5.4.11.

Here is the homework for this week:

Let Φ := ∀ x ♢ φ → ♢ ∀ x φ

For each of the logics QK, QK4, and QT, show either that Φ is provable, or provide a counter-model.

It consists of the following selection of the updated reader:

Exercise 2.4.14

Exercise 7.5.6

Exercise 8.5.1

Exercise 8.5.12

Exercise 10.4.3

1) How can I express the â€˜preservation propertyâ€™, i.e., if a propositional variable (except from p0) is true in a world n of the tree, then it is also true everywhere else above n?

2) While it is quite simple to force the split is the first step (the formula \neg p0 \wedge\Diamond(p0\wedge p1) \wedge\Diamond(p0\wedge \neg p1) works) it is no so simple to produce new branches in successive words.

3) I have made some progress in 1) and 2), but in general, when defining the formula \phi_{n+1}, I tend to use the formula \phi_{n} at least twice as part of the definition. This ends up in a exponential growth of the length of the formulas.

At (1) I can indeed say: since the exercise does not consider transitivity you will have to repeat all your requirements for each level of successors. So, if you want Property A. at all n future levels you will have to say Box A /\ Box Box A /\ ... Box^n A. That is not too elegant but grows linearly in the depth. At (2) you may need to consider fresh variables. Also, you should be sure that your model cannot `'reuse'` worlds. So, that it cannot look back to some earlier world. At (3) I can only say that you should carefully count and keep track of the number of copies. Enjoy working on it.