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The $k$-SAT problem for \L{}-clausal forms has been found to be NP-complete if $k\geq 3$. Similar to Boolean CNF formulas, \L{}-clausal forms are important from a theoretical and practical points of view for their expressive power,…

Logic in Computer Science · Computer Science 2018-06-11 Mohamed El Halaby , Areeg Abdalla

A matched formula is a CNF formula whose incidence graph admits a matching which matches a distinct variable to every clause. We study phase transition in a context of matched formulas and their generalization of biclique satisfiable…

Data Structures and Algorithms · Computer Science 2018-08-07 Miloš Chromý , Petr Kučera

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

The minimum number of clauses in a CNF representation of the parity function $x_1 \oplus x_2 \oplus \dotsb \oplus x_n$ is $2^{n-1}$. One can obtain a more compact CNF encoding by using non-deterministic variables (also known as guess or…

Computational Complexity · Computer Science 2022-05-17 Gregory Emdin , Alexander S. Kulikov , Ivan Mihajlin , Nikita Slezkin

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 show that the CNF satisfiability problem can be solved $O^*(1.2226^m)$ time, where $m$ is the number of clauses in the formula, improving the known upper bounds $O^*(1.234^m)$ given by Yamamoto 15 years ago and $O^*(1.239^m)$ given by…

Data Structures and Algorithms · Computer Science 2020-07-09 Huairui Chu , Mingyu Xiao , Zhe Zhang

Two CNF formulas are called ucp-equivalent, if they behave in the same way with respect to the unit clause propagation (UCP). A formula is called ucp-irredundant, if removing any clause leads to a formula which is not ucp-equivalent to the…

Combinatorics · Mathematics 2026-02-09 Petr Savický

In this work we suggest a new model for generating random satisfiable k-CNF formulas. To generate such formulas -- randomly permute all 2^k\binom{n}{k} possible clauses over the variables x_1, ..., x_n, and starting from the empty formula,…

Combinatorics · Mathematics 2008-07-29 Michael Krivelevich , Benny Sudakov , Dan Vilenchik

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

This paper is devoted to the complexity of the Boolean satisfiability problem. We consider a version of this problem, where the Boolean formula is specified in the conjunctive normal form. We prove an unexpected result that the…

Computational Complexity · Computer Science 2018-07-23 Grigoriy V. Bokov

The 1-in-3 and Not-All-Equal satisfiability problems for Boolean CNF formulas are two well-known NP-hard problems. In contrast, the promise 1-in-3 vs. Not-All-Equal problem can be solved in polynomial time. In the present work, we…

Computational Complexity · Computer Science 2025-05-09 Lorenzo Ciardo , Marcin Kozik , Andrei Krokhin , Tamio-Vesa Nakajima , Stanislav Živný

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

We study the non-canonical method for solving the Satisfiability problem which given by a formula in the form of the conjunctive normal form. The essence of this method consists in counting the number of tuples of Boolean variables, on…

Data Structures and Algorithms · Computer Science 2016-03-03 Anatoly D. Plotnikov

A propositional logic sentence in conjunctive normal form that has clauses of length two (a 2-CNF) can be associated with a multigraph in which the vertices correspond to the variables and edges to clauses. We first show that every such…

Combinatorics · Mathematics 2019-03-19 Vaibhav Karve , Anil N. Hirani

Let $\Phi = (V, \mathcal{C})$ be a constraint satisfaction problem on variables $v_1,\dots, v_n$ such that each constraint depends on at most $k$ variables and such that each variable assumes values in an alphabet of size at most $[q]$.…

Data Structures and Algorithms · Computer Science 2020-11-25 Vishesh Jain , Huy Tuan Pham , Thuy Duong Vuong

Limits on the number of satisfying assignments for CNS instances with n variables and m clauses are derived from various inequalities. Some bounds can be calculated in polynomial time, sharper bounds demand information about the…

Computational Complexity · Computer Science 2017-05-17 Bernd R. Schuh

The topic of this paper is the Finiteness Conjecture for minimally unsatisfiable clause-sets (MUs), stating that for each fixed deficiency (number of clauses minus number of variables) there are only finitely many patterns, given a certain…

Discrete Mathematics · Computer Science 2016-04-06 Oliver Kullmann , Xishun Zhao

The famous Lovasz Local Lemma [EL75] is a powerful tool to non-constructively prove the existence of combinatorial objects meeting a prescribed collection of criteria. Kratochvil et al. applied this technique to prove that a k-CNF in which…

Data Structures and Algorithms · Computer Science 2008-09-15 Robin A. Moser

A monotone CNF formula is a Boolean formula in conjunctive normal form where each variable appears positively. We design a deterministic fully polynomial-time approximation scheme (FPTAS) for counting the number of satisfying assignments…

Data Structures and Algorithms · Computer Science 2014-04-03 Jingcheng Liu , Pinyan Lu

We study the problem of learning a $n$-variables $k$-CNF formula $\Phi$ from its i.i.d. uniform random solutions, which is equivalent to learning a Boolean Markov random field (MRF) with $k$-wise hard constraints. Revisiting Valiant's…

Data Structures and Algorithms · Computer Science 2025-11-05 Weiming Feng , Xiongxin Yang , Yixiao Yu , Yiyao Zhang