>
>
>   > Folding Enumerators
>   > -------------------
>
>   > procedure: collection-keys-fold-left ...
>   > procedure: collection-keys-fold-right ...
>
> I prefer collection-fold-keys-increasing and
> collections-fold-keys-decreasing.

Thats reasonable, though the intent was to have symmetry between the
value and key enumerators.

>   > update.  The returned collection may share structure with the
>   > input collection, but must be distinct with respect to eq? to the
>   > input collection, and the effects of the update must not be
>   > reflected in the input collection.
>
> Why must the returned collection be distinct with respect to eq?
> Suppose I have a set implementation, where sets are represented
> as sorted lists, then it would be natural to let
> (union A '()) return A.

Excellent point.  There really isn't a need to be pointer distinct.  The
important aspect is the latter qualification.  I'll remove that part of
the sentence.

>
>
>   > Functional vs Linear Update
>   > ---------------------------
>   > _Collections_
>
>   > procedure: *-values collection => list
>
> Why not simply name it collection->list ?
> This is similar to vector->list and string->list.
>

Sounds good.  And correspondingly *-keys->list.

	Scott