Title:
  Complete example
Goal:
  Contract the two arguments of the `sum/2' function into a tuple. The 
  selected text is `1,2'.
Parameters:
  [{file,"import.erl"}, {posrange,{141,143}}].
Documentation:
  Accept.
  Both at the definition and the application the two arguments are 
  contracted into a tuple. In the import and export list the arity of the
  function is updated to one. The implicit function is replaced with a
  function expression which calls the new arity-one `sum' funtion from
  the `export' module.
