[Valter Sorana](https://forum.azimuthproject.org/discussion/comment/17036/#Comment_17036) and [Matthew Doty](https://forum.azimuthproject.org/discussion/comment/17038/#Comment_17038) were right. Puzzle 36 should, and now does, say:
> **Puzzle 36.** Every equivalence relation gives a partition as in [Puzzle 29](https://forum.azimuthproject.org/discussion/1963/lecture-10-the-logic-of-partitions/p1). Show that \\(\approx\\) gives the partition \\(P \wedge Q\\).
Whenever I say "meet" there's a 20% chance that I should have said "join", and vice versa. I know what I mean, I just find these words incredibly unevocative. If we called them "greatest lower bound" or "inf" and "least upper bound" and "sup" I would do much better.