Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 2)
    ExpressionList (children 1)
     Function minus (children 1)
      ExpressionList (children 2)
       Function sum (children 1)
        ExpressionList (children 1)
         Function minus (children 1)
          ExpressionList (children 2)
           Literal UInt64_2
           Identifier float64
       Function sum (children 1)
        ExpressionList (children 1)
         Function minus (children 1)
          ExpressionList (children 2)
           Literal UInt64_3
           Identifier float64
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier test_table
