【摘要】 给出了保证最佳一致逼近元唯一存在的哈尔条件的等价定义．用具体例子表明,它在应用上是极其方便的．更多还原

【Abstract】 An equivalent characterization of Haar condition is given in this paper,which guarantees the existence and uniqueness of best uniform approximation.It is shown by example that this equivalent condition is very convenient in application.更多还原