SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Function divide (alias a) (children 1)
     ExpressionList (children 2)
      Function sum (children 1)
       ExpressionList (children 1)
        Identifier t.b
      Literal UInt64_1
    Function sum (children 1)
     ExpressionList (children 1)
      Identifier t.a
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_1 (alias a)
           Literal UInt64_2 (alias b)
