Explain EXPLAIN QUERY TREE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Function max (children 1)
      ExpressionList (children 1)
       Function greaterOrEquals (children 1)
        ExpressionList (children 2)
         Identifier number
         Subquery (children 1)
          SelectWithUnionQuery (children 1)
           ExpressionList (children 1)
            SelectQuery (children 2)
             ExpressionList (children 1)
              Function min (children 1)
               ExpressionList (children 1)
                Identifier x
             TablesInSelectQuery (children 1)
              TablesInSelectQueryElement (children 1)
               TableExpression (children 1)
                Subquery (children 1)
                 SelectWithUnionQuery (children 1)
                  ExpressionList (children 1)
                   SelectQuery (children 2)
                    ExpressionList (children 1)
                     Literal \'1\' (alias x)
                    ExpressionList (children 1)
                     ExpressionList (children 1)
                      Literal UInt64_1
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Function numbers (children 1)
        ExpressionList (children 1)
         Literal UInt64_2
    Set
