SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Function plus (alias b) (children 1)
     ExpressionList (children 2)
      Identifier s.a
      Literal UInt64_2
    Function plus (alias a) (children 1)
     ExpressionList (children 2)
      Identifier s.a
      Literal UInt64_1
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias s) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_10 (alias a)