I apologize for posting the two pictures I mentioned in a recent message in an inaccessible place. I have reposted them on my own website here: http://www.abstractmath.org/Pix%20for%20Wikipedia/ Explanation: Picasa used to allow you to post pix to the web and make them available to everyone. But now it is merged with Google+, where "Public" means anyone with a Google+ account. Sorry for the trouble. Charles Wells -- professional website: http://www.cwru.edu/artsci/math/wells/home.html Gyre&Gimble (math blog): http://www.abstractmath.org/Word%20Press/ abstract math website: http://www.abstractmath.org/MM//MMIntro.htm astounding math stories: http://www.abstractmath.org/MM//MMAstoundingMath.htm personal website: http://www.abstractmath.org/Personal/index.html sixwingedseraph.facebook.com [For admin and other information see: http://www.mta.ca/~cat-dist/ ]