The 'unlock' operation, at least on most central locking systems I've used, is the perfect example of an idempotent unary operation. It doesn't matter how many

The 'unlock' operation, at least on most central locking systems I've used, is the perfect example of an idempotent unary operation. It doesn't matter how many times you apply the 'unlock' operation, it has the same effect as applying it once[1]. However, the 'unlock' operation is not safe[2]. [1]: http://en.wikipedia.org/wiki/Idempotence http://en.wikipedia.org/wiki/Idempotence [2]: http://www.packetizer.com/ws/rest.html http://www.packetizer.com/ws/rest.html