Locally consistent constraint satisfaction problems

Locally consistent constraint satisfaction problems

An instance of a constraint satisfaction problem (CSP) is variable k-consistent if any subinstance with at most k variables has a solution. For a fixed constraint language L, ρk(L) is the largest ratio such that any variable k-consistent instance has a solution that satisfies at least a fraction of ρk(L) of the constraints. We provide an expression for the limit ρ(L) := limk→∞ ρk(L), and show t...

Locally Consistent Constraint Satisfaction Problems

Locally Consistent Constraint Satisfaction Problems with Binary Constraints

An instance of a constraint satisfaction problem is k-consistent if any k constraints of it can be simultaneously satisfied. We focus on constraint languages with a single binary constraint. In this case, the constraint satisfaction problem is equivalent to the question whether there is a homomorphism from an input digraph G to a fixed target digraph H. The instance corresponding to G is k-cons...

Limit Behavior of Locally Consistent Constraint Satisfaction Problems

An instance of a constraint satisfaction problem (CSP) is variable k-consistent if any subinstance with at most k variables has a solution. For a fixed constraint language L, ρk(L) is the largest ratio such that any variable k-consistent instance has a solution that satisfies at least a fraction of ρk(L) of the constraints. We provide an expression for the limit ρ(L) := limk→∞ ρk(L), and show t...

Locally Simultaneous Constraint Satisfaction

Local propagation is often used in graphical user interfaces to solve constraint systems that describe structures and layouts of gures However algorithms based on local propagation cannot solve simultane ous constraint systems because local propagation must solve constraints individually We propose the DETAIL algorithm which e ciently solves systems of constraints with strengths even if they mu...