Exercises for Week 37 (Problem set 2), and new lecture notes

In the new version of the lecture notes, exercises: 1.3, 1.13, 1.14, and 1.17. These are to be handed in, and count towards the final score. Additionally, exercise 1.19 is highly recommended, but does <i>not</i> count.

Note that due to added material, the exercises for Week 37 have new numbers: 1.2, 1.5, 1.7, 1.10.

The lecture notes document is updated. Unfortunately, the section on Wick's Theorem is not complete.