Dijkstra Monads for All, through Section 4.1 (or 4.2)

Let's keep going through Dijkstra Monads for All by Maillard et al. (https://arxiv.org/abs/1903.01237). We're supposed to have finished it through section 3.2, so let's go through sections 3.3 through 4.1 (or if we get ambitious, 4.2).

We'll meet over Zoom and post the meeting URL here a few minutes before meeting start time.