This is Part 4 of an intercontinental 4-part lecture series on the total surgery obstruction. Part 1: http://www.math.sunysb.edu/Videos/Einstein/video_4x3.php?f=1516a-20140418-Ranicki (Stony Brook, 18.4.2014) Part 2: http://www.math.sunysb.edu/Videos/Einstein/video_4x3.php?f=1516b-20140418-Ranicki (Stony Brook, 18.4.2014) Part 3: http://www.dailymotion.com/video/x1sry1t_part-3-the-total-surgery-obstruction-a-ranicki-for-stony-brook_tech (Edinburgh,2.5.2014)
