Posts in category "pfds" Okasaki's PFDS, Chapter 6 December 5, 2015 Okasaki's PFDS, Chapter 5 November 25, 2015 Okasaki's PFDS, Chapter 4 November 8, 2015 Okasaki's PFDS, Chapter 3 November 1, 2015 Okasaki's PFDS, Chapter 2 October 26, 2015