[ dup [] = iff ]else[ done
    ' sortwith nested
    ]'[ nested join do
    behead dup dip nested rot
    witheach
      [ tuck != if
          [ dup dip
            [ nested join ] ] ]
    drop ]                      is uniquewith ( [ --> [ )

  ' [ 1 2 3 5 6 7 8 1 2 3 4 5 6 7 ] uniquewith > echo