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                                        -62-
       
       
       THE POEE ASTROLOGICAL SYSTEM
       
       1.  On your next birthday, return to the place of your birth and, at 
       precisely midnight, noting your birth time and date of observation, 
       count all visible stars.
       
       2.  When you have done this, write to me and I'll tell you what to do 
       next.
       
           The theorem to be proved is that if         LOOK FOR THIS
       any even number of people take seats at        SNOWFLAKE -- IT        
       random around a circular table bearing            HAS MAGIC
       place cards with their names, it is              PROPERTIES
       always possible to rotate the table                  |
       until at least two people are opposite               v
       their cards.  Assume the contrary.  let       [Illustration:  a 
       n be the even number of persons, and let        five-pointed
       their names be replaced by the integers          snowflake]
       0 to n - 1 "in such a way that the place 
       cards are numbered in sequence around 
       the table.  If a delegate d originally 
       sits down to a place card p, then the 
       table must be rotated r steps before he 
       is correctly seated, where r = p - d, 
       unless this is negative, in which case r 
       = p - d + n.  The collection of values 
       of d (and of p) for all delegates is 
       clearly the integers 0 to n - 1, each 
       taken once, but so also is the 
       collection of values of r, or else two 
       delegates would be correctly seated at    The eminent 16th century 
       the same time.  Summing the above         mathematician Cardan so 
       equations, one for each delegate, gives   detested Luther that he
       S - S + nk, where k is an integer and S   altered Luther's birthdate
       = n(n - 1)/2, the sum of the integers     to give him an unfavorable
       from 0 to n - 1.  It follows that n = 2k  horoscope 
       + 1, an odd number."  This contradicts 
       the original assumption.
           "I actually solved this problem 
       some years ago," Rybicki writes, "for a 
       different but completely equivalent 
       problem, a generalization of the non-
       attacking 'eight queens' problem for a 
       cylindrical chessboard where diagonal 
       attack is restricted to diagonals 
       slanting in one direction only."