(Statements
{+(LowOr
  {+(Send
    {+(Identifier)+})+}
  {+(Send
    {+(Identifier)+})+})+}
  (LowAnd
  { (Send
    {-(Identifier)-})
  ->(LowOr
    {+(Send
      {+(Identifier)+})+}
    {+(Send
      {+(Identifier)+})+}) }
    (Send
    { (Identifier)
    ->(Identifier) })))