David wrote:

> Is \\(\leq\\) properly defined in **Puzzle 193**? I think we should have \\(I\leq S\\) for all \\(S\in P(X)\\), but it is not true that \\(X\subseteq S\\) (unless \\(X=S\\)).

Aargh, you're right: \\( (P(X), \subseteq, \cup, \emptyset)\\) is not a monoidal poset.

We could use reverse inclusion instead, but that's too obviously just the same puzzle as the one before, re-expressed using complements. I'm gonna replace this puzzle with one about an old friend, the poset of partitions.