7.6, due March 25th (Part 2)

These blog posts are SO hard for me to remember! I don't know why. Anyway. Here's today's:

• Difficult: I'm TOTALLY lost. I thought I understood what normal meant, but then it says that Na=aN does NOT imply that na=an. Then what DOES it imply? How do you test for normalcy if not like that? That's how I did most of my homework that's due Friday.
• Reflective: It seems like congruence classes always seem to multiply the same way. Which is nice, so long as it never changes.