9.6_ 9.7, due March 5th

1. (difficult) Nothing was particularly difficult. I think permutations could get confusing quickly when the sets are much larger.
2. (reflective) I think the idea of an inverse relation is a natural following from learning of functions and relations. It simply follows that there should exist some inverse of them. Not surprisingly, the rules for these inverses also follow the same as the functional inverses that were taught in early math.