> I would tend to provide a simple but not trivial problem,
> and get them to write it in a familiar procedural style .. then
> show how to convert it to a functional style, and what the
> advantages are. So you'd want to pick a problem which is
> amenable to both kinds of solution.
>
> [...]
>
> One possible project is a small interpreter .. it has
> plenty of scope for variations, and has the advantage
> of being interactive without requiring graphics.
>
This was actually going to be my suggestion.  I'd suggest a very
toned-down version of a mathematics interpreter (think of a baby
Mathematica).  That's the kind of problem that will play well to Ocaml's
strengths, and since you're looking at math-oriented problems, it'd be
reasonably forward.

It'd be really fun to do this post-abstract algebra.  Define Rings and
that kind of stuff as functors, and then go to town.  :-D

~~ Robert Fischer.
Fischer Venture Management Corp