prob016: traffic lights

proposed by  Toby Walsh
tw@cs.york.ac.uk

References

Walter Hower originally proposed this as a CSP benchmark in the Constraints Archive. He claims it has several interesting features: it concerns higher-ary constraints (not just binary ones), it is a real-world problem, it is not too complex, and it shows that local pre-processing may have little or no effect.

Hower, W. Revisiting global constraint satisfaction, Information Processing Letters, 66 (1998) 41-48.