(Statements
  (Comprehension
  { (Identifier)
  ->(Identifier) }
    (Statements
    { (Identifier)
    ->(Identifier) }
    { (Identifier)
    ->(Identifier) }))
  (Comprehension
  { (Plus
    {-(Identifier)-}
    {-(Integer)-})
  ->(Identifier) }
    (Statements
    { (Identifier)
    ->(Identifier) }
    { (Identifier)
    ->(Identifier) })))