The algebraic approach to Constraint Satisfaction Problem led to many developments in both CSP and universal algebra. The notion of absorption was successfully applied on both sides of the connection. This article introduces the concept of absorption, illustrates its use in a number of basic proofs and provides an overview of the most important results obtained by using it. 1998 ACM Subject Cla...

Article history: Received 17 September 2015 Received in revised form 1 February 2016 Accepted 3 February 2016 Available online 4 February 2016

We introduce two frameworks for constraint solving where classical CSPs, fuzzy CSPs, weighted CSPs, partial constraint satisfaction , and others can be easily cast. One is based on a semiring, and the other one on a totally ordered commutative monoid. We then compare the two approaches and we discuss the relationship between them.

Subquadrangles are a natural way in which to represent constraints as they do not restrict any subset of their scope. There are already known methods for converting any given constraint into a set of subquadrangles, but we require a method by which an entire constraint satisfaction problem instance can be converted as a whole. In this paper we present two methods by which we might decompose a g...

A constraint satisfaction problem is a permutation problem if it has the same number of values as variables, all variables have the same domain and any solution assigns a permutation of the values to the variables. The dual CSP interchanges the variables and values; the eeects of combining both sets of variables in a single CSP are discussed.