So last time, Tetra was being enlightened by MC-kun about
definitions. This actually arises from MC-kun using prime
numbers as a motivating example. Primes are megas important in
mathematics and even more important today. The entire branch of
mathematics called number theory is all about studying the
properties of prime numbers. They’re so useful that we’ve done
stuff like extend the notion of prime elements to algebraic
structures called rings or apply analytic techniques to learn
more about them, but we’ll stick with elementary number theory
for now. Now, for hundreds of years, we’d been studying number
theory only because it’s cool and mathematicians love prime
numbers. Last time, I mentioned some examples of math preceding
useful applications. Well, number theory is a really good
example of that, because in the 70s, we found a use for it,
which is its main use today, in cryptography. There have been
some new techniques using some algebra as well, but for the most
part, modern cryptography relies on the ha