Anindya - I like this argument. This could be the slickest possible solution to Puzzle 224.

Now that you mention it, I seem to recall you and Matthew had trouble proving the composite of conjoints is the conjoint of the composite:

\[ \check{FG} \stackrel{?}{=} \check{F} \check{G} .\]

I don't even know if this is true! It would seem strangely asymmetrical for this to be false.