Introduction
Once upon a time when I was starting my studies I bought a book (for it was my first semester and I still bought every book recommended by my professors) quite simply called "Linear Algebra" by Klaus Jänich. In the foreword to the book the author expressed his hope that readers may find whatever they were looking for inside his book, be it mathematics, insight or hope.
So, in that spirit, I wish to express my hope that whoever happens to stumble across my humble page will find whatever he or she might be looking for, be it maths (you'll most likely be disappointed), insight (you be the judge of that, but I somehow doubt it), hope (it's for fools, is it not?) or simply a way to coveniently check for today's chow at the cafeteria. Incidentally I can help you with the former if you're a Mac (OS X 10.4.3+) user and happen to frequent the cafeterias of the Studentenwerk Essen-Duisburg. Quite a lot of "ifs" but hey, it's free!