Tue, 05 Jul 2011 13:28:02 -0600 Kevin Walker fixing proof of 7.1.1 (product thm)
Mon, 04 Jul 2011 11:35:27 -0600 Kevin Walker remark about families of collar maps acting; misc
(0) -300 -100 -30 -10 -2 +2 +10 +30 +100 tip