(Program
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    (Pair
      { (SymbolLiteral) -> (Identifier) }
      { (StringLiteral) -> (StringLiteral) })
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      (Identifier)
      (IntegerLiteral))+}
  {+(Pair
      (Identifier)
      (Boolean))+}
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      (SymbolLiteral)
      (IntegerLiteral))-}
  {-(Pair
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      (Boolean))-}
  {-(Pair
      (SymbolLiteral)
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