
[;1m  is_sofs_set(Term)[0m

  Returns [;;4mtrue[0m if [;;4mTerm[0m appears to be an unordered set, an
  ordered set, or an atomic set, otherwise [;;4mfalse[0m.

  Note that this function will return [;;4mtrue[0m for any term that
  coincides with the representation of a [;;4msofs[0m set. See also note
  on data types.
