> I can hide this code in a trusted kernel: I merely need to be able to
> generate unique types. Frankly, what bsearch code really needed is
> local generative modules -- something like (in SML notation)
>
> val test = let local structure A = Kernel(val a = ...)
>               open A in ... end in ...
>
> According to my reading of the Definition of the Standard ML, this is
> allowed. Alas, neither SML/NJ nor Poly/ML support this pattern.

I don't understand what the 'generative' part means, but are modules
defined inside a let binding equivalent to the above?

Jonathan