I'll send a little sketch showing my solution to the moderators. IFF the 4 outside lamps are equal, then the center lamp will not light, that is until one of the outside lamps is unscrewed.

Radar


[Linked Image]

Edited to add image.


[This message has been edited by pauluk (edited 07-13-2006).]

There are 10 types of people. Those who know binary, and those who don't.