5/19/2018 Lec 12 & 13 1/7 5/19/2018 Lec 12 & 13 2/7 5/19/2018 Lec 12 & 13 3/7 5/19/2018 Lec 12 & 13 4/7 5/19/2018 Lec 12 & 13 5/7 5/19/2018 Lec 12 & 13 6/7 5/19/2018 Lec 12 & 13 7/7