SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Function sum (children 1) ExpressionList (children 1) Function toNullable (children 1) ExpressionList (children 1) Identifier number TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) Function numbers (children 1) ExpressionList (children 1) Literal UInt64_10