Due to the increasing flood of spam mails, I decided to disable my e-mail address. You can still contact me by the following fax number:


Please write only if you want to report errors or if you have useful suggestions. People keep asking me all kinds of questions or want me to solve mathematical problems for them. I simply don't have enough time to answer individual questions or provide individual support. However, I am committed to make my website as useful as possible, and important hints are always welcome.