(Statements
  (Function
    (Empty)
    (Empty)
    (Empty)
  {-(RequiredParameter
    {-(Empty)-}
    {-(Empty)-}
    {-(Identifier)-}
    {-(Empty)-})-}
    (RequiredParameter
      (Empty)
      (Empty)
      (Identifier)
      (Empty))
  {+(RequiredParameter
    {+(Empty)+}
    {+(Empty)+}
    {+(Identifier)+}
    {+(Empty)+})+}
    (StatementBlock
      (Return
      { (Plus
        {-(Identifier)-}
        {-(Identifier)-})
      ->(Times
        {+(Identifier)+}
        {+(Identifier)+}) }))))