8.4, due April 8th

1. I think that theorem 8.25 was kind of confusing, it's basically the same as theorem 8.21 I think, but it was just a little tricky to me to think of the proof for theorem 8.25, who knows, I'll just read it some more.
2. I thought this was a neat section, and I felt like I remembered a lot of stuff that was in this section from other sections, and it was cool to learn about it in a different way!