An improved all-solution SAT solver

All-solution Boolean satisfiability (SAT) solver is used to find the optimized solution, which is implemented by iteratively calling a general SAT solver. Converting the observability of variables to clauses has been proved a good approach of exploiting circuit observability to improve the performance of SAT solver. But the original method can¿t take full use of this property because of total ordering. In this paper, an improved approach without total ordering restriction on variables is proposed. Additionally, a new all-solution solver based on this approach is implemented. The experimental results show the improved approach is very efficient for all-solution SAT problem.