(-∞,+∞)■(a,b)的几种证法及推广

Several Proof and Extension of (-∞,+∞)■(a,b)

使用投影方法巧妙地解决了"如何找到一维离散空间与它的任意子空间之间的拓扑变换"这一问题,从而给出了命题"(-∞,+∞)■(a,b)"的几种证法.受证法的启迪,又将这一命题推广到任意有限维空间中.

Using projection method,a topological transformation from one dimensional discrete space （-∞,＋∞） to its subspace（a,b）was given,several proof methods of the proposition （-∞,＋∞）≌（a,b） were also glven,then the proposition was expanded to arbitrary finite dimensional space.