(Program
  (Match
    (Send
      (Identifier))
    (Statements
      (Pattern
        (Statements
          (Send
          { (Identifier)
          ->(Identifier) }))
        (Statements
        {+(Send
          {+(Identifier)+})+}
        {+(Send
          {+(Identifier)+})+}
        {-(Pattern
          {-(Statements
            {-(Send
              {-(Identifier)-})-}
            {-(Send
              {-(Identifier)-})-})-}
          {-(Statements
            {-(Send
              {-(Identifier)-})-}
            {-(Statements)-})-})-})))))