Improved Bound for the PPSZ/Schöning-Algorithm for 3-SAT

The PPSZ Algorithm presented by Paturi, Pudlak, Saks, and Zane in 1998 has the nice feature that the only satisfying solution of a uniquely satisfiable 3-SAT formula can be found in expected running time at most O(1.3071^n ). Its bound degenerates when the number of solutions increases. In 1999, Sch ning proved an O(1.3334^n ) bound for 3-SAT. In 2003, Iwama and Tamaki combined both algorithms to yield an O(1.3238^n ) bound. We tweak the PPSZ-Bound to get a slightly better contribution to the combined algorithm and prove an O(1.32216^n ) bound.

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