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