procedure roman(n)		#: convert integer to Roman numeral
   local arabic, result
   static equiv

   initial equiv := ["","I","II","III","IV","V","VI","VII","VIII","IX"]

   integer(n) > 0 | fail
   result := ""
   every arabic := !n do
      result := map(result,"IVXLCDM","XLCDM**") || equiv[arabic + 1]
   if find("*",result) then fail else return result
end