Looks like the 4th edition has introduced at least one typo not present in the 3rd -- a brief web search reveals that others complain about this too. Anyway: Page 194, section 4.3, the two first matrices are both the identity. The first is supposed to be the identity, the other is supposed to have zeroes on the main diagonal. Page 218, last two lines: Replace i=3,4 and j=3,4 by i=4,5 and j=4,5 respectively. Page 238, The definition of epsilon(p) is wrong. It should be 1 when U>1-p and 0 when U<=1-p.