Errata

(Thanks to Markus Linckelmann) • The first sum in Conjecture 2.10 should start from i = 0. • The relations ∼D in Proposition 5.1 should be replaced by ∼〈u〉 meaning that the corresponding elements are conjugate in ND(〈u〉) (reported by René Reichenbach). • In Lemma 6.13(i) and (ii) the group C15 × C4 should be replaced by C15 o C4. • At the end of the proof of Lemma 7.5, the claims about normalizers and centralizers are not correct. The argument is still elementary and left to the reader. • The Cartan matrices in Theorem 8.1(5a) and (5b) should be interchanged. • Second matrix on p. 189 should be 4 1 2 2 1 4 2 2 2 2 4 1 2 2 1 4 .