The use of the 'M[y,x]' notation found in Biørn's book and some of the seminar exercises is voluntary. I.e. you my use it if you like it, but no questions at the exam require knowledge of this specific notation.
The link to "3 lecture notes" should now work again
The contact student for ECON4160 is Michael Kloss, email michael.kloss@student.hu-berlin.de