Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

CSP stands for the constraint satisfaction problem.

0
votes
0answers
44 views

Find the maximum induced (weighted) subgraph with edge weights greater than some minimum

I have a (fully connected) weighted undirected graph. I want to find a maximal induced subgraph whose edge weights are all above some minimum value. Or, if not a maximal subgraph, then with some ...
8
votes
1answer
362 views

complexity of a constraint satisfaction promise problem

(This is the "upper end" of my question from over 10 months ago on cs.stackexchange. That question and the "lower end" I asked here over 8 months ago, which I also have a bounty on, are both ...
7
votes
1answer
149 views

What are the hardness results known for CSP over $\mathbb{F}_q$?

I found two related papers, There is a UGC hardness result here, https://www.cs.cmu.edu/~venkatg/pubs/papers/qaryCSP.pdf A kind of a stronger result might be found in these two other papers, http://...
6
votes
1answer
284 views

Does every NO instance of this promise problem have a local refutation?

For the following equivalent questions, you choose whether-or-not the 3 variables in a clause must be distinct. Is there an integer $k$ such that for all 3-SAT formulas $\mathcal{F}$ without ...
10
votes
1answer
221 views

Complexity of digraph homomorphism to an oriented cycle

Given a fixed directed graph (digraph) $D$, the $D$-COLORING decision problem asks whether an input digraph $G$ has a homomorphism to $D$. (A homomorphism of $G$ to $D$ is a mapping $f$ of $V(G)$ to $...
0
votes
0answers
126 views

CSP-problem, based on context-free grammar

I'm trying to solve a CSP (Constraint-Satisfaction-Problem), which is based on arbitrary context-free grammars. A quick example: Let's say we have a context-free grammar with the following production ...
1
vote
1answer
137 views

Confusion in 2012 paper by Austrin and Håstad regarding hardness of approximating GLST

The paper in question is "On the Usefulness of Predicates", Per Austrin, Johan Håstad (arXiv:1204.5662 [cs.CC]). On page 13, Example 8.2 they define a predicate $P$ which is $GLST$ with an ...
4
votes
1answer
72 views

Definition of Projection Measure in the characterization of strong approximation Resistance in a paper by Khot et al

I'm reading a paper about Constraint Satisfaction Problems, specifically "A Characterization of Strong Approximation Resistance", Subhash Khot, Madhur Tulsiani, Pratik Worah (ECCC TR13-075). The ...
4
votes
1answer
108 views

How to estimate the probability of distribution of a variable in a Constraint Satisfication Problem

Consider that we have a state space of n random variables, for simplicity, the variable value can be 0 or 1. Each variable has its probability distribution when it is not constrained, also for ...
6
votes
0answers
120 views

General Results for Complicated Constraint Satisfaction Problem

Consider the following problem: on a finite two-dimensional grid (say the grid points are vertices of a graph), I need to color the vertices in such a way to satisfy the existence and nonexistence of ...
5
votes
2answers
359 views

Learnability of constraint satisfaction problems CSPs?

This may sound more like a soft question but I am struggling to find an answer for it. While the learnability of Bayesian Networks and other graphical models are well detailed in the literature of ...
1
vote
1answer
136 views

Encoding quadratic constraints in a constraint satisfaction problem into SAT

It seems like most constraint satisfaction problems can be posed in terms of SAT. The question is two fold: How can any CSP with quadratic constraints be framed as a satisfiability instance Is ...
3
votes
1answer
223 views

How is this graphical representation of SAT/CSP instances called?

Given a CNF formula (SAT problem), we can construct the constraint/dependency graph, which contains a vertex for each variable and a hyperedge for each clause. Same goes for CSPs, where we have a ...
1
vote
0answers
75 views

Constraint problem

I have encountered a constraint problem and I would like to know if there exists a name and implemented solvers for this type of constraint problem. My constraints are of the forms. 1) $CONSTANT \in ...
12
votes
1answer
237 views

Schaefer's theorem and CSPs of unbounded width

Schaefer's dichotomy theorem shows that each CSP problem over $\{0,1\}$ is either solvable in polynomial time or is NP-complete. This applies only for CSP problems of bounded width, excluding SAT and ...
4
votes
1answer
187 views

Constraint satisfaction problem on a graph

Consider the set $S = \{1, \dots, n\}$ and $n$ subsets $S_i \subseteq S$ of size $d$ each (think of $S_i$ as neighborhoods of vertex $i$ in some $d$-regular graph, although the graph structure is not ...
10
votes
2answers
6k views

Is the N Queens problem NP-hard?

The N-queen problem is this: Input : N Output : A placement of N "queens" on an NXN chessboard such that no two queens lie on the same row, column or diagonal. Doing a google search on this, I ...
7
votes
2answers
329 views

What is known about the H-factor problem?

Background The $\mathcal{H}$-factor problem (a.k.a. the degree prescribed factor problem, or the degree prescribed subgraph problem) is defined as follows: Given a graph $G=(V,E)$ and a set $H_v \...
3
votes
1answer
223 views

A variant of betweenness problem

Is there any non-trivial approximation algorithm for a variant of betweenness problem: namely, we want to minimize the number of unsatisfied triples rather than to maximize the number of satisfied ...
26
votes
2answers
1k views

Ladner's Theorem vs. Schaefer's Theorem

While reading the article "Is it Time to Declare Victory in Counting Complexity?" over at the "Godel's Lost Letter and P=NP" blog, they mentioned the dichotomy for CSP's. After some link following, ...
2
votes
1answer
168 views

hardness of approximation result for a Min-CSP, by reduction from PCPs

Reduction from PCPs allow us to prove hardness of approximation results for a number of constraint satisfaction problems. I've seen such a reductions only for Max-CSPs. Is this possible only for Max-...
12
votes
1answer
262 views

Any results on binary boolean CSP beyond the fixed-parameter tractability of almost 2SAT problem?

Let $\varphi$ be a 2CNF formula and $k$ a nonnegative integer. It is proved in this paper that the problem of deciding whether one can delete at most $k$ clauses to make $\varphi$ satisfable, is fixed-...
9
votes
0answers
427 views

When is CSP faster than SMT/SAT?

Do CSP solvers have any fundamental advantages over SMT/SAT solvers, in terms of performance? The answer is going to be problem dependent, so I should also ask: what does a problem need to contain in ...
22
votes
3answers
574 views

Educational Source or Survey on Analysis of Semidefinite Program?

When designing approximation algorithms one sometimes solves a semidefinite program followed by a rounding step. An often used example to illustrate this is Max-Cut. (See e.g. Approximation Algorithms ...
6
votes
2answers
340 views

What relation is between constraint satisfaction problems and constraint programming?

Are programs written in the constraint programming (CP) paradigm more expressive than problems defined as constraint satisfaction problem (CSP)? Wikipedia says about Constraint_programming: ...
17
votes
5answers
372 views

Open or Interactive Constraint Satisfaction

In the past, I implemented coordination models using SAT and regular constraint satisfaction as the core workhorse in their engines. Continuing in this line of work, I would like to make the models ...
16
votes
3answers
528 views

UGC hardness of the predicate $NAE(x_1, …, x_\ell)$ for $x_i \in GF(k)$?

Background: In Subhash Khot's original UGC paper (PDF), he proves the UG-hardness of deciding whether a given CSP instance with constraints all of the form Not-all-equal(a, b, c) over a ternary ...
10
votes
1answer
259 views

CSPs with unbounded fractional hypertree width

At SODA 2006, Martin Grohe and D$\acute{\rm a}$niel Marx's paper "Constraint solving via fractional edge covers" (ACM citation) showed that for the class of hypergraphs $H$ with bounded fractional ...
12
votes
1answer
296 views

Finding the penumbra of a Constraint Satisfaction Problem

The following question has come up a number of times when testing the security of a system or model. Motivation: Software security flaws often come not from bugs due to valid inputs, but bugs ...
10
votes
3answers
441 views

Hard gaps in maximum constraint satisfaction problems?

An equivalent formulation of PCP theorem is: For Max 3-SAT it is $NP$-hard to distinguish between satisfiable formulas and formulas where at most $r$-fraction of the clauses are satisfiable (for some $...