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