[ 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