pdf: http://www.ipt.ntnu.no/~stanko/files/Courses/TPG4230/2019/Lecture_notes/20190405.pdf
video: http://www.ipt.ntnu.no/~stanko/files/Courses/TPG4230/2019/Videos/20190405.mp4
class exercise: http://www.ipt.ntnu.no/~stanko/files/Courses/TPG4230/2019/Class_files/20190405/Class_exercise.pdf