(Statements
  (Comprehension
    (KeyValue
    { (Identifier)
    ->(Identifier) }
    { (Identifier)
    ->(Identifier) })
    (Statements
    {+(Identifier)+}
    {+(Identifier)+}
    {-(Statements
      {-(Identifier)-}
      {-(Identifier)-})-}
    {-(Identifier)-}))
  (Comprehension
    (KeyValue
    { (Identifier)
    ->(Identifier) }
    { (Integer)
    ->(Identifier) })
    (Statements
    {+(Statements
      {+(Identifier)+}
      {+(Identifier)+})+}
    { (Identifier)
    ->(Identifier) }
    {-(Identifier)-})))