If you had any idea... how many times I had to rewrite this book, I do think you would be surprised. As it is, I do believe that there are still weak parts, but that is not the main problem. This book is meant as a problem solving tool and the more it develops, the more problems it can solve. It made the writing hard, because as I progressed further, I had to go back and fix up things that I had developed a better understanding of. Many books about sciences are updated in their later editions. This page is meant to be a collection, chapter by chapter, of what I want to add or update in a future edition. Because how this has developed, these may be some of the most important points of the book. They will undoubtedly need development and to be fit in to what exists in the book, but they have to be put somewhere.