> Maybe I'm incredibly dense, but this seems tautologically true, and not worth mentioning. Could somebody kindly explain what I'm missing? If this seems so tr

> Maybe I'm incredibly dense, but this seems tautologically true, and not worth mentioning. Could somebody kindly explain what I'm missing? If this seems so trivial to you, simply write down the proof. If you are not really mathematically gifted, you will soon see where the problem is ... ;-)