A Note on Redundant Rules in Rule-Based Constraint Programming
نویسنده
چکیده
Constraint propagation can sometimes be described conveniently in a rule-based way. Propagation is then fixpoint computation with rules. In the typical case when no specific strategy guides the fixpoint computation, it is preferable to have a minimal set of rules. We propose a natural criterion for redundancy of a rule, and describe a test for a class of rules. Its relevance is demonstrated by applying it to several rule sets from two important approaches to automatic rule generation.
منابع مشابه
Constraint programming viewed as rule-based programming
We study here a natural situation when constraint programming can be entirely reduced to rule-based programming. To this end we explain first how one can compute on constraint satisfaction problems using rules represented by simple first-order formulas. Then we consider constraint satisfaction problems that are based on predefined, explicitly given constraints. To solve them we first derive rul...
متن کاملIntegration and Optimization of Rule-Based Constraint Solvers
One lesson learned from practical constraint solving applications is that constraints are often heterogeneous. Solving such constraints requires a collaboration of constraint solvers. In this paper, we introduce a methodology for the tight integration of CHR constraint programs into one such program. CHR is a high-level rule-based language for writing constraint solvers and reasoning systems. A...
متن کاملUsing Program Analysis for Integration and Optimization of Rule-based Constraint Solvers
ABSTRACT. One lesson learned from practical applications is that constraints are often heterogeneous. Solving such constraints requires a collaboration of constraint solvers. In this paper, we introduce a methodology for the tight integration of CHR constraint solver programs into one such program. CHR is a high-level rule-based language for writing constraint solvers and reasoning systems. A c...
متن کاملGuard Reasoning in the Refined Operational Semantics of CHR
Constraint Handling Rules (CHR) is a high-level programming language based on multi-headed guarded rules. The original highlevel operational semantics of CHR is very nondeterministic. Recently, instantiations of the high-level operational semantics have been proposed and implemented, removing sources of nondeterminism and hence allowing better execution control. Rule guards may be redundant und...
متن کاملSchedulers and redundancy for a class of constraint propagation rules
We study here schedulers for a class of rules that naturally arise in the context of rule-based constraint programming. We systematically derive a scheduler for them from a generic iteration algorithm of (Apt 2000). We apply this study to so-called membership rules of (Apt and Monfroy 2001). This leads to an implementation that yields a considerably better performance for these rules than their...
متن کامل