This rule is a prevention of deadlock.If a deadlock is occured,each of the four necessary conditions must hold.So by ensuring that at least one of these conditions cannot hold, we can prevent the occurrence of a deadlock.When a philosopher makes a request for the first chopstick, do not satisfy the request only if there is no other philosopher with two chopsticks and if there is only one chopstick remaining.

Taking into account the requirements of chopsticks is one at a time. And no priority