SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 4)
    Identifier a1
    Identifier b1
    Identifier a2
    Identifier b2
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier tab2
     TableJoin (children 1)
      Function and (children 1)
       ExpressionList (children 2)
        Function equals (children 1)
         ExpressionList (children 2)
          Function plus (children 1)
           ExpressionList (children 2)
            Identifier b1
            Literal UInt64_1
          Function plus (children 1)
           ExpressionList (children 2)
            Identifier a2
            Literal UInt64_1
        Function equals (children 1)
         ExpressionList (children 2)
          Function plus (children 1)
           ExpressionList (children 2)
            Identifier a1
            Literal UInt64_4
          Function plus (children 1)
           ExpressionList (children 2)
            Identifier b2
            Literal UInt64_2
