Newsgroups: sci.math From: hsbrand@cs.vu.nl (HS Brandsma) Subject: Re: Topology question (please help) Date: Fri, 9 Feb 1996 09:48:37 GMT Chih-Huei Wang (cwang@attila.stevens-tech.edu) wrote: : Is it true that the complement of a compact subset of an : infinite dimensional Banach space is contractible? : If so, where can I look up a proof? : Thanks in advance. Look in Bessaga en Pelcsynki's book topics in infinite-dimensional topology. There you'll find the proof that the complement of a sigma-compact set in such a space is homeomorphic to the original space, so in particular it is contractible Henno Brandsma