The description for set-map says "duplicate elements are omitted as in
the set constructor" but the description of the constructor says nothing
about duplicate elements.

In addition, the description of set-map also says

 > If the elements are the same in the sense of eqv?, it is
unpredictable which one will be preserved in the result.

This sounds like it would apply to set and list->set. But why is eqv?
mentioned here and not the equality predicate?

Finally the phrase "duplicate elements are omitted" is confusingly
worded to me, since it sounds like if two or more elements compare equal
none of them will be inserted, instead of the (I think) intended meaning
of "if two or more elements compare equal, only one will be inserted".

-- Peter McGoron