Deductive Generation of Constraint Propagation Rules

Deductive Generation of Constraint Propagation Rules

Constraint propagation can often be conveniently expressed by rules. In recent years, a number of techniques for automatic generation of rule-based constraint solvers have been developed, most of them using a generate-and-test approach. We examine a generation method that is based on deduction. A solver (i. e., a set of rules) for a complex constraint is obtained from one or several weaker solv...

Operational Semantics and Connuence of Constraint Propagation Rules Operational Semantics and Connuence of Constraint Propagation Rules

Constraint Handling Rules (CHR) allow one to specify and implement both propagation and simpliication for user-deened constraints. Since a propagation rule is applicable again and again, we present in this paper for the rst time an operational semantics for CHR that avoids the termination problem with propagation rules. In previous work AFM96], a suucient and necessary condition for the connuen...

Description Logic with Constraint Propagation Rules

The challenges of the Semantic Web endeavour in knowledge representation and reasoning prompted a wealth of research in combining description logic (DL) as ontology languages (e.g. OWL) with logic programming for rule-based reasoning. General issues of combining and integrating formalisms have to be faced such as the type of combination, conceptual simplicity and tractability. Even though const...

Constraint Propagation for Linear Recursive Rules

There are many ways in which the query answering process for deductive databases may be optimised. Many of these methods rely on applying constraints as soon as possible, to avoid the production and later rejection of facts which are not relevant to the query. This propagation of constraints is much simpler for left-linear programs than for many others. In this paper we show how to transform ri...

Programming Constraint Propagation in Rea tive Rules