-Recall that a monad requires a singleton function `mid : P-> MP`, and a
-composition operator `>=> : (P->MQ) -> (Q->MR) -> (P->MR)`. The type for
-the composition operator stated here corrects a typo in the class handout.
-Also, in the handout we called `mid` `𝟭`. But now we've decided that `mid`
-is better. (Think of it as "m" plus "identity", not as the start of "midway".)
+Recall that a monad requires a singleton function <code>mid : P-> <u>P</u></code>, and a
+composition operator like <code>>=> : (P-><u>Q</u>) -> (Q-><u>R</u>) -> (P-><u>R</u>)</code>.