On 18 Oct 2003 at 15:47, psu wrote: Talking of Borel sets of the real line, you need to be quiet mathematically sophisticated to be able to write down a subset of the real line which is not a Borel set. I don't know of any such subset occuring naturally in aplications which is not a Borel set.
Every Open (and closed) set is Borel, every countable intersection of opens is Borel (G-deltas), every countable union of Gdeltas is Borel, GSigmaDeltas, and so on without stop. Kjetil Halvorsen > Can anyone explain, in non-technical jargon, what is meant by the > concept of a Borel set? I am looking for an intuitive way of recognizing > a Borel set when I see one. Perhaps my question is naive, but maybe > someone can understand what i'm asking nevertheless. > > Thanks! > > . > . > ================================================================= > Instructions for joining and leaving this list, remarks about the > problem of INAPPROPRIATE MESSAGES, and archives are available at: > . http://jse.stat.ncsu.edu/ . > ================================================================= . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
