(Program
  (Function
    (Empty)
    (Empty)
    (Identifier)
    (RequiredParameter
      (Empty)
      (Empty)
      (Empty)
      (Assignment
        (Identifier)
        (Empty)))
    (RequiredParameter
      (Empty)
      (Empty)
      (Empty)
      (Assignment
        (Identifier)
        (Empty)))
    (
      (Function
        (Empty)
        (Empty)
        (Identifier)
        (RequiredParameter
          (Empty)
          (Empty)
          (Empty)
          (Assignment
            (Identifier)
            (Empty)))
        (RequiredParameter
          (Empty)
          (Empty)
          (Empty)
          (Assignment
            (Identifier)
            (Empty)))
        (
          (Call
            (Identifier)
            (Identifier)
            (Empty))
          (Call
            (Identifier)
            (Identifier)
            (Empty)))))))