Page "Dining philosophers problem" Paragraph 5

Each philosopher must alternately think and eat.

However, a philosopher can only eat spaghetti when he has both left and right forks.

Each fork can be held by only one philosopher and so a philosopher can use the fork only if it's not being used by another philosopher.

After he finishes eating, he needs to put down both the forks so they become available to others.

A philosopher can grab the fork on his right or the one on his left as they become available, but can't start eating before getting both of them.