Coupon Collectors, q-Binomial Coefficients and the Unsatisfiability Threshold

  title={Coupon Collectors, q-Binomial Coefficients and the Unsatisfiability Threshold},
  author={Alexis C. Kaporis and Lefteris M. Kirousis and Yannis C. Stamatiou and Malvina Vamvakari and Michele A. A. Zito},
The problem of determining the unsatisfiability threshold for random 3-SAT formulas consists in determining the clause to variable ratio that marks the (experimentally observed) abrupt change from almost surely satisfiable formulas to almost surely unsatisfiable. Up to now, there have been rigorously established increasingly better lower and upper bounds to the actual threshold value. An upper bound of 4.506 was announced by Dubois et al. in 1999 but, to the best of our knowledge, no complete… 
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