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