SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 3)
    Identifier v.x
    Identifier r.a
    Function sum (children 1)
     ExpressionList (children 1)
      Identifier c
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias v) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_1 (alias x)
           Literal UInt64_2 (alias c)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias r) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_1 (alias x)
           Literal UInt64_2 (alias a)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier v.x
        Identifier r.x
   ExpressionList (children 1)
    Identifier v.x
