procedure main()
   X := [ [1,2,3], [2,3,1], [3,1,2])                       # A list of lists
   Sort(X)                                                 # vanilla sort
   Sort(X,"ordering","numeric","column",2,"reverse")       # using optional parameters
end

procedure Sort(X,A[])                                      # A[] provides for a variable number of arguments
   while a := get(A) do {
      case a of {
         "ordering" :  op := case get(A) | runerr(205,a) of {
            "lexicographic"|"string":  "<<"
            "numeric": "<"
            default:  runerr(205,op)
            }
         "column"   : col := 0 < integer(col := get(A)) | runerr(205,col)
         "reverse"  : reverseorder := reverse
         default: runerr(205,a)
         }
   return (\reverseorder|1)(bubblesortf(X,\c|1,\op|"<<"))  # reverse or return the sorted list
end