Finite domain propagation solvers effectively represent the possible values of variables by a set of choices which can be naturally modelled as Boolean variables. In this paper we describe how we can mimic a finite domain propagation engine, by mapping propagators into clauses in a SAT solver. This immediately results in strong nogoods for finite domain propagation. But a naive static translati...

This work presents a novel strategy for improving SAT solver performance by using concurrency. Rather than aiming to parallelize search, we use concurrency to aid a conventional CDCL search procedure. More concretely, our work extends a conventional CDCL SAT solver with a second computation thread, which is solely used to strengthen the clauses learned by the solver. This provides a simple and ...

Boolean satisfiability (SAT) and its extensions are becoming a core technology for the analysis of systems. The SAT-based approach divides into three steps: encoding, preprocessing, and search. It is often argued that by encoding arbitrary Boolean formulas in conjunctive normal form (CNF), structural properties of the original problem are not reflected in the CNF. This should result in the fact...

Everyone laughed. What’s funny about this? If I had said, “Let’s take the short way,” it would have been understood that the shortness used in my description also provided a motivation for taking that route. Since I used the word “muddy” instead, it seemed as if I wanted to run that way because it was muddy, as if I enjoyed sloshing through the mud. Very often different parts of a clause are co...

The writ of habeas corpus and the right to due process have long been linked together, but their relationship has never been more unsettled or important. Following the September 11, 2001 attacks, the United States detained hundreds of suspected terrorists who later brought legal challenges using the writ. In the first of the landmark Supreme Court cases addressing those detentions, Hamdi v. Rum...

This paper took an experimental approach and examined island constraints in Korean. Among many island constraints, this study took a Complex NP island constraint, and the experiment was designed with 3 related factors: presence vs. absence of island, matrix clause vs. embedded clause, and scrambling. The analysis results illustrated that the presence/absence of complex NP island did not play a ...

It has been observed empirically that clause learning does not significantly improve the performance of a SAT solver when restricted to learning clauses of small width only. This experience is supported by lower bound theorems. It is shown that lower bounds on the runtime of width-restricted clause learning follow from resolution width lower bounds. This yields the first lower bounds on width-r...

Information retrieval is an integral component of any database management system. Temporal database management systems should offer user-friendly and powerful means of retrieval of data according to temporal criteria. The From clause is an important component of the Select statement: it identifies the underlying relations from which the information is to be retrieved and allows the declaration ...

Abstract This paper sketches a grammar of English relative clause constructions (including infinitival and reduced relatives) based on the notions of construction type and type constraints. Generalizations about dependency relations and clausal functions are factored into distinct dimensions contributing constraints to specific construction types in a multiple inheritance type hierarchy. The gr...