Grading knowledge

If you are sitting in a basement room without a view — not to mention the bars in front of the windows — and writing a book, then you better have good company. I had the best company you could imagine. Waltraud Hiltl, Katja Markert, Martin Romacker, Klemens Schnattinger, Andreas Klee and I shared very little o?ce space, but plenty of chocolate, co?ee, champagne, and enthusiasm for our research. North German coolness and creativity sprang mostly from my colleagues in the second ?oor. I learned a lot from and laughed a lot with Nobi Br¨oker, Susanne (Sue) Schacht, Manfred Klenner, Peter Neuhaus, Stefan Schulz, and Michael Strube. I thank my friend and partner Angela R¨osch for motivational and te- nical support and for living together with someone who cares about strange things, works too much and does not improve in any way over the years. Special thanks go to my family who sometimes wondered what was going on when I started talking enthusiastically about “semantics”, but they never let wane their encouragement for me. Kornel Marco provided great service by implementing parts of the system presented in this book. Joe Bush helped me polish up the text with his capabilities as an Amer