OT : RIP Martin Gardner

In case you've not already heard, I have just been told that Martin Gardner has passed away. He was, of course, responsible for many excellent books of mathematical puzzles. He had a defintie knack of being able to make something simple enough to understand but still keeping enough mathematics there to be worthwhile. The world is certainly a poorer place without him. He certainly inspered me to love mathemaitcs. Had I not read his books some years ago, my life would have been very different. I don't think I am exagerating if I say that without his books I would not have passed A-level mathematics... True story : Many years ago I was given a couple of his books as a Newtonsday presnet. Once contained a chapter on base -2 arithmeatic. I spent the next day or so designing a base -2 full-adder circuit and soldering it up. Never found any practical use for it, but... -tony