(Program
  (Module
    (Identifier))
  (Function
    (Empty)
    (Identifier)
    ([]))
  (Function
    (Empty)
    (Identifier)
    (Call
      (Identifier)
      (Empty)))
  (Function
    (Empty)
    (Identifier)
    (
      (Call
        (Identifier)
        (Empty))
      (Call
        (Identifier)
        (Empty))))
  (Function
    (Empty)
    (Identifier)
    (
      (Call
        (Identifier)
        (Empty))
      (Call
        (Identifier)
        (Empty)))))