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We call a CNF formula linear if any two clauses have at most one variable in common. Let Linear k-SAT be the problem of deciding whether a given linear k-CNF formula is satisfiable. Here, a k-CNF formula is a CNF formula in which every…

Discrete Mathematics · Computer Science 2007-08-20 Dominik Scheder

We show that the CNF satisfiability problem (SAT) can be solved in time $O^*(1.1199^{(d-2)n})$, where $d$ is either the maximum number of occurrences of any variable or the average number of occurrences of all variables if no variable…

Data Structures and Algorithms · Computer Science 2024-11-13 Sanjay Jain , Tzeh Yuan Neoh , Frank Stephan

We call a CNF formula linear if any two clauses have at most one variable in common. Let m(k) be the largest integer m such that any linear k-CNF formula with <= m clauses is satisfiable. We show that 4^k / (4e^2k^3) <= m(k) < ln(2) k^4…

Discrete Mathematics · Computer Science 2008-07-10 Dominik Scheder

Form a random k-SAT formula on n variables by selecting uniformly and independently m=rn clauses out of all 2^k (n choose k) possible k-clauses. The Satisfiability Threshold Conjecture asserts that for each k there exists a constant r_k…

Statistical Mechanics · Physics 2009-09-29 Dimitris Achlioptas , Cristopher Moore

We introduce the problem of finding a satisfying assignment to a CNF formula that must further belong to a prescribed input subspace. Equivalent formulations of the problem include finding a point outside a union of subspaces (the…

Data Structures and Algorithms · Computer Science 2021-08-16 Vikraman Arvind , Venkatesan Guruswami

A boolean formula in a conjuctive normal form is called a (k,s)-formula if every clause contains exactly k variables and every variable occurs in at most s clauses. We prove the existence of a (k, 4 * (2^k/k))-CNF formula which is…

Discrete Mathematics · Computer Science 2008-10-13 Heidi Gebauer

We obtain the smallest unsatisfiable formulas in subclasses of $k$-CNF (exactly $k$ distinct literals per clause) with bounded variable or literal occurrences. Smaller unsatisfiable formulas of this type translate into stronger…

Discrete Mathematics · Computer Science 2024-07-22 Tianwei Zhang , Tomáš Peitl , Stefan Szeider

While 3-SAT is NP-hard, 2-SAT is solvable in polynomial time. Austrin, Guruswami, and H\r{a}stad roved a result known as "$(2+\varepsilon)$-SAT is NP-hard" [FOCS'14/SICOMP'17]. They showed that the problem of distinguishing k-CNF formulas…

Discrete Mathematics · Computer Science 2021-09-10 Alex Brandts , Marcin Wrochna , Stanislav Živný

The satisfiability problem is NP-complete but there are subclasses where all the instances are satisfiable. For this, restrictions on the shape of the formula are made. Darman and D\"ocker show that the subclass MONOTONE $3$-SAT-($k$,1)…

Computational Complexity · Computer Science 2023-12-11 Hannah Van Santvliet , Ronald de Haan

We consider the following problem. Given a 2-CNF formula, is it possible to remove at most $k$ clauses so that the resulting 2-CNF formula is satisfiable? This problem is known to different research communities in Theoretical Computer…

Data Structures and Algorithms · Computer Science 2008-04-18 Igor Razgon , Barry O'Sullivan

We describe an algorithm to solve the problem of Boolean CNF-Satisfiability when the input formula is chosen randomly. We build upon the algorithms of Sch{\"{o}}ning 1999 and Dantsin et al.~in 2002. The Sch{\"{o}}ning algorithm works by…

Computational Complexity · Computer Science 2019-03-27 Andrea Lincoln , Adam Yedidia

In the Maxmin E$k$-SAT Reconfiguration problem, we are given a satisfiable $k$-CNF formula $\varphi$ where each clause contains exactly $k$ literals, along with a pair of its satisfying assignments. The objective is transform one satisfying…

Computational Complexity · Computer Science 2025-08-04 Shuichi Hirahara , Naoto Ohsaka

Open questions with respect to the computational complexity of linear CNF formulas in connection with regularity and uniformity are addressed. In particular it is proven that any l-regular monotone CNF formula is XSAT-unsatisfiable if its…

Computational Complexity · Computer Science 2018-01-19 Bernd. R. Schuh

Majority-SAT is the problem of determining whether an input $n$-variable formula in conjunctive normal form (CNF) has at least $2^{n-1}$ satisfying assignments. Majority-SAT and related problems have been studied extensively in various AI…

Computational Complexity · Computer Science 2021-11-16 Shyan Akmal , Ryan Williams

Let F be a random k-SAT formula on n variables, formed by selecting uniformly and independently m = rn out of all possible k-clauses. It is well-known that if r>2^k ln 2, then the formula F is unsatisfiable with probability that tends to 1…

Computational Complexity · Computer Science 2007-05-23 Dimitris Achlioptas , Yuval Peres

We establish the satisfiability threshold for random $k$-SAT for all $k\ge k_0$, with $k_0$ an absolute constant. That is, there exists a limiting density $\alpha_*(k)$ such that a random $k$-SAT formula of clause density $\alpha$ is with…

Probability · Mathematics 2021-04-16 Jian Ding , Allan Sly , Nike Sun

Regular signed SAT is a variant of the well-known satisfiability problem in which the variables can take values in a fixed set V \subset [0,1], and the `literals' have the form "x \le a" or "x \ge a". We answer some open question regarding…

Discrete Mathematics · Computer Science 2011-12-08 Christian Laus , Dirk Oliver Theis

Let $\Phi$ be a random $k$-SAT formula in which every variable occurs precisely $d$ times positively and $d$ times negatively. Assuming that $k$ is sufficiently large and that $d$ is slightly below the critical degree where the formula…

Combinatorics · Mathematics 2016-11-11 Amin Coja-Oghlan , Nick Wormald

Maximum satisfiability is a canonical NP-hard optimization problem that appears empirically hard for random instances. Let us say that a Conjunctive normal form (CNF) formula consisting of $k$-clauses is $p$-satisfiable if there exists a…

Probability · Mathematics 2007-05-23 Dimitris Achlioptas , Assaf Naor , Yuval Peres

In this paper, we prove that the general CNF satisfiability problem can be solved in $O^*(1.0638^L)$ time, where $L$ is the length of the input CNF-formula (i.e., the total number of literals in the formula), which improves the previous…

Data Structures and Algorithms · Computer Science 2022-08-18 Junqiang Peng , Mingyu Xiao
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