For successful software verification, model checkers must be capable of handling a large number of program variables. Traditional, BDD-based model checking is deficient in this regard, but SAT-based model checking, i.e. bounded model checking (BMC), shows some promise. However, unlike traditional model checking, for which time systems have been thoroughly researched, BMC is less capable of mode...

In this paper, a novel hybrid and complete approach for propositional satisfiability, called SATHYS (Sat Hybrid Solver), is introduced. It efficiently combines the strength of both local search and CDCL based SAT solvers. Considering the consistent partial assignment under construction by the CDCL SAT solver, local search is used to extend it to a model of the Boolean formula, while the CDCL co...

This paper presents a reduction from the problem of solving parity games to the satisfiability problem in propositional logic (SAT). The reduction is done in two stages, first into difference logic, i.e. SAT combined with the theory of integer differences, an instance of the SAT modulo theories (SMT) framework. In the second stage the integer variables and constraints of the difference logic en...

In computational complexity theory, a decision problem is NP-complete when it is both in NP and NP-hard. Although a solution to a NP-complete can be verified quickly, there is no known algorithm to solve it in polynomial time. There exists a method to reduce a SAT (Satifiability) problem to Subset Sum Problem (SSP) in the literature, however, it can only be applied to small or medium size probl...

A new form of SAT-based symbolic model checking is described. Instead of unrolling the transition relation, it incrementally generates clauses that are inductive relative to (and augment) stepwise approximate reachability information. In this way, the algorithm gradually refines the property, eventually producing either an inductive strengthening of the property or a counterexample trace. Our e...

Modern SAT solvers are highly dependent on heuristics. Therefore, benchmarking is of prime importance in evaluating the performances of different solvers. However, relevant benchmarking is not necessarily straightforward. We present our experiments using the IBM CNF Benchmark on several SAT solvers. Using the results, we attempt to define guidelines for a relevant benchmarking methodology, usin...

When tackling a computationally challenging combinatorial problem, one often observes that some solution approaches work well on some instances, while other approaches work better on other instances. This observation has given rise to the idea of building algorithm portfolios [5]. Leyton-Brown et al. [1], for instance, proposed to select one of the algorithms in the portfolio based on some feat...

An analysis was conducted to examine the market visibility of small aircraft as a transportation mode in competition with automobile and scheduled commercial air travel by estimating the pool of users that would potentially switch on-demand air travel due to cost/time saving. These new aircraft greatly increase the practicality of regional aircraft as a transportation mode that can avoid the co...

In Bounded Model Checking (BMC), the search for counterexamples of increasing lengths is translated into a sequence of satisfiability (SAT) checks. It is natural to try to exploit the similarity of these SAT instances by forwarding clauses learned during conflict analysis from one instance to the next. The methods proposed to identify clauses that remain valid fall into two categories: Those th...

The logistic sigmoid function curve provides an accurate description of the baroreflex input-output relationship and is the most commonly used equation for this purpose. The threshold (Thr) and saturation (Sat) values for the baroreflex are commonly defined as the values of mean arterial pressure (MAP) at which the reflexly controlled variable (e.g., heart rate or sympathetic nerve activity) is...