We introduce a greedy local search procedure called GSAT for solving propositional satisfiability problems. Our experiments show that this procedure can be used to solve hard, randomly generated problems that are an order of magnitude larger than those that can be handled by more traditional approaches such as the Davis-Putnam procedure or resolution. We also show that GSAT can solve structured...

A meta-answer is a set of statements that assert various properties of an answer to a database uery. These statements may qualify the validity or the completeness o 1 the answer, or they may characterize the answer abstractly. Meta-answers add meaning and insight to standard database answers. We describe an extension to the relational database model for representing properties of the stored dat...