> A modulo-sequence lets you use wrap-around indexes (like -1 or bignum)
> but it's really a finite sequence, so *-size returns a true value, and
> collection-fold halts.
>
> An infinite-sequence really is infinite, even if its internal
> representation isn't, so *-size returns #f, and collection-fold does not
> halt.
>
> Based on this, I say: Tighten up the definitions of *-size and fold to
> make this more obvious, but otherwise no changes. There's no need for
> finite-collection?, because it's essentially equivalent to *-size under
> this interpretation.

Correct.  I've done just that.

	Scott