SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 3)
    Identifier tab1.a1
    Identifier tab1_copy.a1
    Identifier tab1.b1
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier tab1_copy
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Function plus (children 1)
         ExpressionList (children 2)
          Identifier tab1.b1
          Literal UInt64_3
        Function plus (children 1)
         ExpressionList (children 2)
          Identifier tab1_copy.b1
          Literal UInt64_2