a Rabbi , a Priest and an engineer were to be executed by guillotine. The Rabbi is up first, praying fervently for God to save him. As luck would have it, the mechanism is faulty and the blade remains hung up. By the rules of the time he is set free. Next up is the Priest, praying just as hard. Somehow, the mechanism remains hung up and he to is set free. Finally the engineer is brought up. Just as he is about to be strapped down he looks up and says, "Hang on. I see what the problem is.'