This paper introduces the concept of ordient for binary relations (preferences), a relative of the concept of gradient for functions (utilities). Ordients have a natural economic interpretation as marginal rates of substitution. Some examples of ordientable binary relations include the...

A symmetric difference metric topology on the collection of binary relations on a countably infinite set provides a new setting for the study of properties of preferences and, as an illustration, is used to lend credence and meaning to some simple intuitions about properties of binary relations....

Sustainable development of the new energy industry requires continuous input from professional talents. The new energy industry will continue to grow in importance, and the characteristics of the necessary cross-discipline talents that will promote its development are becoming more and more...

In a choice situation, it is usually assumed that the agents select the maximal elements inaccordance with their preference relation. Nevertheless, there are situations in which a selectioninside this maximal set is needed. In such a situation we can select randomly some of thesemaximal...