Note from the HTML-editor

A note on the formulas: In the original article, greek characters aswell as formulas were used in the text. As there is no possibility for greek characters and formulas in HTML-text at the moment, I chose to use gif-pictures instead. This means that if your browser does not support graphics, you will not be able to view paragraph 4. Should you really be interested in the mathematics, please contact us and we will make some arrangement.

If you are on a slow connection, it is advisable to turn image loading off for the next few pages as there a a lot of gif-images to come.

It also means that, in certain parts, the font sizes will not match. If this really disturbs you, you could try changing your default font size.

Please let me know if this works, or if you have a better alternative.

Marcelo Müller