Section 7.9

Difficult: The most difficult part of this section for me was Lemma 7.49. The proof of Lemma 7.49 was hard for me to follow, and I didn't quite understand why the authors used the elements xy, xd, cy, and cd. It would be helpful for me to go over it in class.

Reflective: The concept of symmetric and alternating groups is interesting. Since the alternating group A(n) is the set of all even permutations in S(n), what function does the set of all odd permutations have? What makes even permutations special? Why does the fact that they are even make it an "alternating" group? I am interested to see where this discussion and these definitions take us.