Correct version of example 3.21 ¡­

Correct version of example 3.21 is available under the examples link. No important differences in the conclusions compared to what was shown in the lectures.

Exercises to Friday 30. september: 3.13 problem 1 and 2.

On Friday 7. october, there will be two hours exercises and no lectures.

On Friday 14. October there will be neither lectures nor exercises. Relax!