SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function arraySort (children 1)
     ExpressionList (children 1)
      Function arraySymmetricDifference (children 1)
       ExpressionList (children 2)
        Literal Array_[\'a\', \'b\']
        Literal Array_[\'a\', \'c\']