Questions tagged [sat-solvers]
Questions regarding solver programs for the boolean satisfiability problem.
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resolving in CDCL
When resolving in Conflict driven clause learning, it is the case that if you resolve a conflicting clause with the reason of the negation of one of his literals, then this results in another ...
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Can you help me find some examples of 3co-SAT for 4 variables?
I've been studying the examples of 3co-SAT recently.
It's easy to find an example of one variable.
$(x_1\lor x_1\lor x_1)\land (\overline{x_1}\lor \overline{x_1}\lor \overline{x_1})$
Examples of 2 ...
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what does **input** mean for the $3SAT$ question? Is it the number of variables $n$ or the number of clauses $m$
We know that $3SAT \in NP$,
and the definition of $NP$ is as follows:
$NP$ is the class of languages that have polynomial time verifiers.
But I have a question:
what does input mean for the $3SAT$ ...
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Time-complexity of evaluating a CNF formula
Given a Boolean formula over $n$ variables in CNF and a partial assignment to it, all the algorithms I can think of to evaluate the assignment run in time $\Theta(n^2)$. Is it possible to do it in $O(...
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MAX-SAT 2-Approximation algorithm
I have the two following questions:
I know SAT -> MAX-SAT but how can I show that if MAX-SAT is solved in polynomial time then SAT is solved in polynomial time as well?(I guess using approximation ...
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prove that if $SAT\notin Size(2^{n/100})$ then CorrectSATSolver$\in P$
I need to prove that if $SAT\notin Size(2^{n/100})$ then CorrectSATSolver$\in P$.
Where CorrectSATSolver $= \{C | C(\varphi) = 1 \iff \varphi$ is satisfiable$\}$. In other words, CorrectSATSolver ...
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How overapproximation of boolean abstraction function works?
I just found that if original formula is unsat, using boolean abstraction function can result in sat. Clearly this is overapproximate. I wonder if I have contingent formula, does that means my boolean ...
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What are efficient approaches to implement unit propagation in DPLL-based SAT solvers?
I'm trying to decompose deduction steps of DPLL algorithm -- unit propagation and pure literal elimination -- for parallelization. However, I want a baseline and asymptotic analysis to compare to my ...
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Quantum Boolean SAT algorithm?
Is there a quantum SAT algorithm, a quantum analogue of the DPLL or CDCL algorithms?
Note: I'm not looking for the quantum analogue of the Boolean satisfiability problem (though that would be ...
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How to determine if clause will change the satisfiability of the 3SAT formula?
I have satisfiable 3SAT formula like:
(x1 or x2 or x3) and (not x1 or x2 or not x3)
and some clause which is not in this formula ...
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Stalmarck's method: x ≡ x → z, does z have to be true?
I have been researching Ståmarck's method 1. In the paper cited here, some rules are given. Rules are made of triplets (x, y, z) such that:
y $\to$ z $\equiv$ x
where x, y and z are booleans which ...
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Non-trivial reduction form SAT to $3$-SAT
Looking for any idea for reduction from $SAT \leq 3-SAT$ where $SAT$ is known to have $d$ variables at most in each clause. I am looking for a reduction in which the resulting formula will not depend ...
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Why is this SAT problem hard and what can I do about it?
For a graph theory problem I need to solve hundreds of millions of CNF problems that typically have around 200 variables and 15,000 clauses no larger than 10.
By default I use glucose, which usually ...
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Getting maximum information regarding question key from students answers
You are given a multi-dimensional array with each index consisting of two attributes (Score, Answers)
Each element in the array represents the test results of a student on a True or False exam. Each ...
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Three dimensional matching expressed as SAT
The posting in the website Embedding SATISFIABILITY into 3-DIMENSIONAL MATCHING seeks $3SAT$ as a $3$ dimensional matching instance.
I am looking to solve the converse problem. How to solve three ...
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SAT solvers that can compute prime implicants and/or minimization
I'm looking into computing the prime implicants of a Boolean function. I have found many different algorithms in the literature, many of them relying on SAT solvers. However, I have not been able to ...
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Which features can be considered for neural network based SAT solving?
I'm trying to implement SAT solver, based on backtracking algorithm and BCP. This SAT solver is trying to pick one literal from each clause, from 3-CNF SAT instances. I've implemented a neural network ...
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Proving using a SAT solver that KB entails D
Suppose you're given this KB:
$$KB = (A, A ⇒ B, A ⇒ C, B ∧ C ⇒ D)$$
How would you show using a SAT solver that $KB \vDash D$?
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How often can a learned clause cause this solver to backtrack?
The is an improvement to the X3SAT solver I described in What is wrong with this simple proof of P=NP? I have fixed the flaw found in that solver. Now, I want to know how often the solver described ...
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Solving largely monotone SAT formulas
I just wonder if solving largely monotone SAT formulas (meaning most clauses do not contain negated literals, but some do) is in any way easier than general SAT formulas? In other words, are there ...
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Is there any algorithm for 3SAT problem that is fast and relatively easy to implement?
Here is the description for 3SAT satisfiability problem. I already know about the DPLL algorithm, but it's implementation is pretty complex. I would like some algorithm that is relatively simpler but ...
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How to leverage the fact that I'm solving 1000's of very similar SMT instances?
I have a core SMT solver problem consisting of 100,000 bit-vector array clauses, and one 10000-dimensional bit-vector array. Then, my program takes as input k << 100,000 new clauses, and adds ...
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Are there competitions for integer programming?
Are there competitions for integer programming like there are for SAT and MAXSAT?
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Find a list of actions that result in desired state
I have a problem that I need to solve, and I'm looking for which area of computer science (algorithms. etc) would be appropriate to solve this problem.
In the system we have a list of actions that a ...
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What are the differences between symbolic execution and SAT solvers?
My understanding is that symbolic execution only deals with specific paths and bad patterns, while SAT solvers, or satisfiability modulo theories in general, provide a much more robust analysis of the ...
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Clarification on "clause learning" in DPLL algorithm
I am struggling to understand the idea of conflict-driven clause learning, in particular, I can not understand why the clause we 'learned' is a substantially new (i.e. the clause database does not ...
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Is it feasible to solve this subset cover problem with SAT solver?
The problem is to find $\mathcal{S}$, a minimal collect of subsets of $\{1,\dots, 17\}$ such that the two conditions are satisfied:
if $S \subseteq \mathcal{S}$ then $|S|=6$;
for any $A \subseteq \{1,...
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CNF satisfiability with a bound on number of clauses
Consider the CNF-sat problem with n literals and k clauses. If k scales linearly in n, we get np-completeness (e.g., 3-sat where each literal appears at most 4 times). Do we still get np-completeness ...
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Practical hard 3-sat instances
The $3-SAT$ problem is known to be NP-complete problem. Which means that (as far as I understand), unless $P \neq NP$, for every algorithm $A$ which decides $3-SAT$, $A$ runs in super polynomial time (...
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Non-Boolean SAT
I was wondering about the complexity of SAT tests with variables $x_i = 0 \lor 1 \lor 2 \dots \lor n$, with clauses being of the form $x_i = a \implies x_j \neq b$. When $n=2$, we have 2SAT, which has ...
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Random restarts for unsatisfiable instances
In the worst case, Boolean satisfiability (assuming P!=NP) takes exponential time. Nonetheless, modern SAT solvers using variants of DPLL, are able to solve enough instances to be useful in practice.
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Can an optimization algorithm be "universal"?
I am wondering if a Bayesian Optimization framework (e.g. Google's Vizier) can be used in lieu of a traditional solver like Gurobi or CPLEX.
In trying to answer this question, I realized that I don'...
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Sum of unique integers to cnf constraint
As a study project I try to solve the kakuro puzzle problem using SAT SOLVER.
I can't really find an efficient way to convert the sum of k unique integers (1...9) to a CNF constraint.
What I had in ...
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Encoding a "not-k-out-of-n" constraint for SAT solvers
I'm finding myself needing to encode a "not-k-out-of-n" constraint in a SAT solver.
The "at-most-k-out-of-n" constraint for SAT solvers is something I can find research about -- this paper by Frisch ...
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Determine if a graph has exactly 1 cycle using a SAT solver
I have a connected undirected graph whose edges are either enabled or disabled. I want to create a set of clauses that are SAT iff all enabled edges are part of a single loop.
If I assert that each ...
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Is there a correspondence of steps between DPLL and sequent-calculus?
Is there a correspondence between the steps in using DPLL to find out that a formula in propositional logic is unsatisfiable and using sequent calculus to prove that its negation is valid?
And given ...
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Translation of diagnosis problem to SAT
I have the following diagnosis problem:
h(A): z1 = not(in1)
h(D): z2 = not(in2)
h(B): z3 = z1 or z2
h(C): out1 = not(z3)
h(E): out2 = not(z3)
This is an image of the system:
I have an observation ...
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Fine-grained complexity of 3-CNF formula evaluation
It's well known that 3-SAT is in NP, which means that one can evaluate a 3-CNF formula in polynomial time. However, I was wondering what the tightest upper bound is for formula verification, expressed ...
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Why not do these checks on the number of clauses in 3-SAT?
I've been writing a 3-SAT solver for fun and comparing its performance against the solver pycosat. My solver vastly outperforms pycosat in two special cases, where I solve by doing simple, obvious ...
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Detect non existence of a cycle in a graph using Datalog : SMTLIB Format for Z3
I want to detect the non existence of a cycle in a graph using Datalog (which is a declarative logic programming language).
The proposed solution was:
...
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Is any sudoku solver an SAT solver?
I have recently created a sudoku solver using C#, which outputs the solution to a sudoku after a reasonable amount of time in many cases. I have used the basic sudoku SAT-reduction (i.e. x111 meaning ...
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General Understanding of SMT Solving Across Multiple Theories
My first question was a little too simplified in that it turned out to be an integer linear programming problem solvable with the Simplex Method. However, what I think I am wondering about is how to ...
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How the Abstract DPLL Algorithm Works in SAT Solving
I have come across many definitions of the DPLL algorithm but haven't been able to follow them. The ones that are closest to making sense to me are the ones based on state-transition systems with ...
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How a SMT / SAT Solver Generates Valuations for this Example
First, an example of a set of constraints which turned out not to be solvable (I don't think):
...
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Counting solutions of a particular type in HORN SAT
I am interested in counting the number of solutions of a particular type (say #) in HORN SAT. I have 2 questions concerning the same.
Suppose we have a HORN SAT -: $(x_1) \land (x_2 \implies x_1)$, ...
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How to find a nearly-optimal covering of a set using SAT?
I have recently started thinking about application of SAT in solving different problems and how I can encode those problems into a SAT problem.
I think one of the interesting problems where SAT ...
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How hard is APPROXIMATE-#SAT? [closed]
It is well known that the problem of counting the satisfying assignments of SAT, namely the problem #SAT, is #P-complete.
It is also suspected (somewhat less widely) that even deciding SAT should ...
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SAT solver optimizations of DPLL for unsatisfiable formulas [duplicate]
I am implementing a SAT solver based on DPLL algorithm, and it works fine on small formulas and larger satisfiable problems. My case split is based on a tree like structure, where every branch is ...
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If a CNF contains only Horn and Xor clauses, then what is the complexity of determining Satisfiability?
If a CNF contains only Horn and Xor clauses, and does not contain clauses of other types, then can its Satisfiability be determined in polynomial time?
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What is the complexity of determining Satisfiability of a CNF containing both Horn and Dual Horn clauses?
If a CNF contains both horn and dual horn clauses and does not contain clauses of other types, then can its Satisfiability always be determined in polynomial time?
If the answer to the above problem ...
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