In this lecture we prove that $\operatorname{Tor}$ is a well defined functor, and establish its basic properties. We then define homology with coefficients, and state and prove the Universal Coefficient Theorem.

##### Remark

In lecture today I lazily left about half the proofs as "exercises" for Problem Sheet L. This resulted in Problem Sheet L having about 20 questions... So I relented and added proofs for most of the bits I didn't do in class. (Now Problem Sheet L only has six questions!)  😇