Section 3.2.5

Difficult: I got lost when they used Lemma 3.2.5.1 in their proof of the infinite primes. I guess that probably comes from the fact that I didn't understand the Lemma that clearly when I read it in the first place.

Reflective: Another proof. I am not sure what this tells us about the primes though, but I am sure that it adds something of value.