(Program
  (Package
    (Identifier))
  (Function
    (Empty)
    (Identifier)
    ([])
    (
    { (Identifier)
    ->(Identifier) }
      (Negate
      { (Identifier)
      ->(Identifier) })
      (Not
        (ReceiveOperator
        { (Identifier)
        ->(Identifier) }))
      (Pointer
        (Call
        { (Identifier)
        ->(Identifier) }
          ([])
          (Empty)))
      (Complement
      { (Identifier)
      ->(Identifier) })
      (Reference
      { (Identifier)
      ->(Identifier) })
      (ReceiveOperator
      { (Identifier)
      ->(Identifier) }))))