Inapproximability Results for Set Splitting and Satisfiability Problems with no Mixed Clauses
ثبت نشده
چکیده
منابع مشابه
On Approximation Hardness of the Minimum 2SAT-DELETION Problem
The Minimum 2SAT-Deletion problem is to delete the minimum number of clauses in a 2SAT instance to make it satisfiable. It is one of the prototypes in the approximability hierarchy of minimization problems [8], and its approximability is largely open. We prove a lower approximation bound of 8 √ 5 − 15 ≈ 2.88854, improving the previous bound of 10 √ 5 − 21 ≈ 1.36067 by Dinur and Safra [5]. For h...
متن کاملNotes on the PCP Theorem and Complexity of Approximations
We know that a number of important optimization problems are NP-hard to solve exactly. Today we begin the study of the complexity of finding approximate solutions. There is a fundamental difficulty in proving hardness of approximation results. All the NPcompleteness proofs for graph problems before 1990 can be essentially described as follows: we start from the computation of a generic non-dete...
متن کاملCourse ”Proofs and Computers“, JASS’06 Probabilistically Checkable Proofs
Before introducing probabilistically checkable proofs, I shortly give an overview of the historical development in the field of inapproximability results which are closely related to PCPs. A foundational paper from Johnson in 1974 states approximation algorithms and inapproximability results for Max SAT, Set Cover, Independent Set, and Coloring. While the decision problems for various problems,...
متن کاملSolving Optimal Satisfiability Problems Through Clause - Directed A
Real-world applications, such as diagnosis and embedded control, are increasingly being framed as OpSAT problems problems of finding the best solution that satisfies a formula in propositional state logic. Previous methods, such as Conflict-directed A*, solve OpSAT problems through a weak coupling of A* search, used to generate optimal candidates, and a DPLL-based SAT solver, used to test feasi...
متن کاملAn early sign of satisfiability
This note considers checking satisfiability of sets of propositional clauses (SAT instances). It shows that unipolar sets of clauses (containing no positive or no negative clauses) provide an early sign of satisfiability of SAT instances before all the clauses become satisfied in the course of solving SAT problems. At this sign the processing can be terminated by unipolar set termination, UST t...
متن کامل