Procedure to remove duplicate elements from a list. The returned list will be sorted.

[RS]: You don't even need a procedure for this, because that's exactly what ''[lsort] -unique'' does:
 interp alias {} lrmdups {} lsort -unique
Testing this [interp alias] interactively with a [tclsh]:
 % lrmdups {foo bar grill bar foo}
 bar foo grill

[SS]: Well.. it depends. '''lsort -unique''' does it in O(NlogN), while the trivial algorithm to remove duplicated
elements runs in O(N). So if your list is very very long [lsort] may not be an option. Also you may like to
have a stable algorithm that will not alter the order of non-duplicated elements.