Problems- back

Scott W. Williams

1. An angel is stuck on an infinite sheet of graph paper, he can hop from square to adjacent square. Everytime the angel hops, the devil can knock out any square, so the angel can't ever go there. Can the devil trap the angel? What if the graph paper is bounded on two sides? (I think this is due to Conway) yes- see http://www.ai.mit.edu/people/deniz/problems.html

History of Mathematics induced by unsolved problems: http://forum.swarthmore.edu/~isaac/mathhist.html

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