SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function equals (children 1)
     ExpressionList (children 2)
      Literal UInt64_0
      Function position (children 1)
       ExpressionList (children 2)
        Literal \'abc\'
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal \'bcdef\'