(Program
  (Comprehension
  { (Identifier)
  ->(Identifier) }
    (
    { (Identifier)
    ->(Identifier) }
    { (Identifier)
    ->(Identifier) }))
  (Comprehension
  { (Identifier)
  ->(Plus
    {+(Identifier)+}
    {+(Integer)+}) }
    (
    { (Identifier)
    ->(Identifier) }
    { (Identifier)
    ->(Identifier) })))