English
Related papers

Related papers: Unsatisfiable CNF Formulas need many Conflicts

200 papers

A special case of the satisfiability problem, in which the clauses have a hierarchical structure, is shown to be solvable in linear time, assuming that the clauses have been represented in a convenient way.

Computational Complexity · Computer Science 2008-02-03 Donald E. Knuth

We study relationship among versions of the Knapsack Problem where variables take values in Z and the number of them is fixed. In particular, we construct a finitely presented group where the problem of solvability of exponential equations…

Group Theory · Mathematics 2021-05-17 Oleg Bogopolski , Aleksander Ivanov

This work resolves the open problem of strong singularity ($\alpha(z)> 1$) in nonlocal Kirchhoff-type equations with variable exponents through five original theorems that collectively establish a comprehensive theory. Beginning with…

Analysis of PDEs · Mathematics 2026-03-31 M. H. M. Rashid

The aim of this article is to generalize logics of formal inconsistency ($\textbf{LFI}$s) to systems dealing with the concept of incompatibility, expressed by means of a binary connective. The basic idea is that having two incompatible…

Logic · Mathematics 2022-02-23 Marcelo Esteban Coniglio , Guilherme Vicentin de Toledo

The fixed-template constraint satisfaction problem (CSP) can be seen as the problem of deciding whether a given primitive positive first-order sentence is true in a fixed structure (also called model). We study a class of problems that…

Computational Complexity · Computer Science 2022-05-11 Kristina Asimi , Libor Barto , Silvia Butti

We extend the convergence law for sparse random graphs proven by Lynch to arbitrary relational languages. We consider a finite relational vocabulary $\sigma$ and a first order theory $T$ for $\sigma$ composed of symmetry and…

Combinatorics · Mathematics 2020-06-15 Lázaro Alberto Larrauri

We demonstrate a family of propositional formulas in conjunctive normal form so that a formula of size $N$ requires size $2^{\Omega(\sqrt[7]{N/logN})}$ to refute using the tree-like OBDD refutation system of Atserias, Kolaitis and Vardi…

Computational Complexity · Computer Science 2007-05-23 Nathan Segerlind

The constraint satisfaction probem (CSP) is a well-acknowledged framework in which many combinatorial search problems can be naturally formulated. The CSP may be viewed as the problem of deciding the truth of a logical sentence consisting…

Logic in Computer Science · Computer Science 2007-05-23 Hubie Chen

The runtime performance of modern SAT solvers on random $k$-CNF formulas is deeply connected with the 'phase-transition' phenomenon seen empirically in the satisfiability of random $k$-CNF formulas. Recent universal hashing-based approaches…

Discrete Mathematics · Computer Science 2017-02-28 Jeffrey M. Dudek , Kuldeep S. Meel , Moshe Y. Vardi

Recently it has been proved that, assuming that there is an almost disjoint family of cardinality (2^{\mathfrak c}) in (\mathfrak c) (which is assured, for instance, by either Martin's Axiom, or CH, or even $2^{<\mathfrak c=\mathfrak c$})…

Functional Analysis · Mathematics 2012-07-13 Jose Luis Gamez-Merino , Juan B. Seoane-Sepulveda

We investigate parameterizing hard combinatorial problems by the size of the solution set compared to all solution candidates. Our main result is a uniform sampling algorithm for satisfying assignments of 2-CNF formulas that runs in…

Discrete Mathematics · Computer Science 2017-08-04 Jean Cardinal , Jerri Nummenpalo , Emo Welzl

On any closed Riemannian manifold of dimension greater than $7$, we construct examples of background physical coefficients for which the Einstein-Lichnerowicz equation possesses a non-compact set of positive solutions. This yields in…

Analysis of PDEs · Mathematics 2015-05-13 Bruno Premoselli , Juncheng Wei

The CSP of a first-order theory $T$ is the problem of deciding for a given finite set $S$ of atomic formulas whether $T \cup S$ is satisfiable. Let $T_1$ and $T_2$ be two theories with countably infinite models and disjoint signatures.…

Logic · Mathematics 2023-06-22 Manuel Bodirsky , Johannes Greiner

In the lambda calculus a term is solvable iff it is operationally relevant. Solvable terms are a superset of the terms that convert to a final result called normal form. Unsolvable terms are operationally irrelevant and can be equated…

Logic in Computer Science · Computer Science 2019-03-14 Á. García-Pérez , P. Nogueira

The random k-SAT model is the most important and well-studied distribution over k-SAT instances. It is closely connected to statistical physics; it is used as a testbench for satisfiability algorithms, and average-case hardness over this…

Computational Complexity · Computer Science 2017-03-08 Noah Fleming , Denis Pankratov , Toniann Pitassi , Robert Robere

We show that a randomly chosen 3-CNF formula over n variables with clauses-to-variables ratio at least 4.4898 is, as n grows large, asymptotically almost surely unsatisfiable. The previous best such bound, due to Dubois in 1999, was 4.506.…

Discrete Mathematics · Computer Science 2008-07-24 J. Diaz , L. Kirousis , D. Mitsche , X. Perez-Gimenez

We show how to construct a non-2-colorable k-uniform hypergraph with (2^(1 + o(1)))^k edges. By the duality of hypergraphs and monotone k-CNF-formulas this gives an unsatisfiable monotone k-CNF with (2^(1 + o(1)))^k clauses

Discrete Mathematics · Computer Science 2009-11-05 Heidi Gebauer

The degrees of freedom of MIMO interference networks with constant channel coefficients are not known in general. Determining the feasibility of a linear interference alignment solution is a key step toward solving this open problem. Our…

Information Theory · Computer Science 2015-05-13 Cenk M. Yetis , Syed A. Jafar , Ahmet H. Kayran

We study the number of queries needed to identify a monotone Boolean function $f:\{0,1\}^n \rightarrow \{0,1\}$. A query consists of a 0-1-sequence, and the answer is the value of $f$ on that sequence. It is well-known that the number of…

Let $m(n, k)$ be the maximum number of prime implicants that any $k$-CNF on n variables can have. We show that $3^{n/3} \le m(n,2) \le (1+o(1))3^{n/3}$.

Discrete Mathematics · Computer Science 2015-10-20 Navid Talebanfard