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Redundant Sudoku rules

Published online by Cambridge University Press:  30 October 2012

BART DEMOEN  and
MARIA GARCIA DE LA BANDA
BART DEMOEN
Affiliation:
Department of Computer Science, KU Leuven, Belgium (e-mail: bart.demoen@cs.kuleuven.be)
MARIA GARCIA DE LA BANDA
Affiliation:
Faculty of Information Technology, Monash University, Australia (e-mail: Maria.GarciaDeLaBanda@monash.edu)
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Abstract

The rules of Sudoku are often specified using 27 all_different constraints, referred to as the big constraints. Using graphical proofs and exploratory logic programming, the following main and new result is obtained: Many subsets of six of these big constraints are redundant (i.e., they are entailed by the remaining 21 constraints), and six is maximal (i.e., removing more than six constraints is not possible while maintaining equivalence). The corresponding result for binary inequality constraints, referred to as the small constraints, is stated as a conjecture.

Keywords

Sudokuall_different constraintsinequalitiesmaximal redundancy
Type
Technical Notes
Information
Theory and Practice of Logic Programming , Volume 14 , Issue 3 , May 2014 , pp. 363 - 377
Copyright
Copyright © Cambridge University Press 2012 

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References

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