ABSTRACT
Of course, the diagram is supposed to simultaneously represent ‡ocks of hyperbolic quadrics as well as ‡ocks of quadratic cones, and maybe parallelisms of these structures. The very obvious clue to decoding the diagram is ‘what does the
red indicate?’Those of you who knew me back in the day recall when I had red hair as well as ‘una barba rossa’will explain the red. But the red has a nice shape also, the hint being: What is 14? Unfortunately, there is a bit more— what do the yellow points above the 14 suggest (think noble thoughts)? In any case, in spite of the tedious explanation of the diagram, I
very much hope you enjoyed the book — Cheers, Norm Johnson
