From: Fred Galvin Subject: Re: Covering with totally- bounded sets Date: Sat, 2 Sep 2000 21:44:04 -0500 Newsgroups: sci.math Summary: [missing] On 2 Sep 2000, Jose wrote: > Let (X,d) be a metric space / there exists a countable subset D of X > such that its adherence is X. Question: > There exist Borel sets C_n n=1,2,... such that: > i) X is the union of C_n n=1,2,... > ii) Each C_n is totally-bounded (for every E>0 there exist a finite > subset {x_1,...,x_p} of C_n / C_n is included in the union of the > balls with center x_i and radious E i=1,...p)????? > If this is false, is it true when (X,d) is complete???? In an infinite-dimensional Hilbert space, each totally bounded set is nowhere dense. By the Baire category theorem, countably many such sets cannot cover the space. -- "Any clod can have the facts, but having opinions is an art."--McCabe