One of the main objectives of science and engineering is to help people select the most beneficial decisions. To make these decisions, we must know people's preferences, and we must have information about different possible consequences of the decisions. Since information is never absolutely accurate and precise, we must also have information about the degree of certainty of every piece of information. All these types of information naturally lead to partial orders: for preferences, a b means that b is preferable to a. This relation is used in decision theory. For events, a b means that a can...