prob041: The n-Fractions Puzzle

proposed by

Alan Frisch, Christopher Jefferson, Ian Miguel, Toby Walsh

frisch@cs.york.ac.uk, caj@cs.york.ac.uk, ianm@cs.york.ac.uk, tw@4c.ucc.ie

References

Probably the first appearance of the 3-fractions puzzle in the constraints literature is:

C. Schulte, G. Smolka. Finite Domain Constraint Programming in Oz: A Tutorial.

The following paper shows how a basic model of the 3-fractions puzzle can be improved automatically:

A.M. Frisch, I. Miguel, T. Walsh. Extensions to Proof Planning for Generating Implied Constraints. Proceedings of the 9th Symposium on the Integration of Symbolic Computation and Mechanized Reasoning (Calculemus 01), 130-141, 2001.

Using hand-reformulation, the following paper discusses how different using symmetry-breaking schemes on the 3-fractions puzzle, followed by the derivation of implied constraints, can lead to models of varying quality.

A.M. Frisch, C. Jefferson, I. Miguel. Symmetry-breaking as a Prelude to Implied Constraints: A Constraint Modelling Pattern. APES Technical Report 75-2003.

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