بازسازي منطق ترجيح

Aristotle can be treated as a pioneer of Logic of Preference. In modern times some such distinguished researchers as Soren Hallden, C.H. Von Wright, R. Chisholm, N. Rescher and R. Jeffrey have contributed considerably in reviving and developing this part of logical science. Among logical relations playing fundamental role in the Logic of Preference, one is that of P and S: P meaning "P is preferred to q" or "P is better than q" and S meaning "P is equivalent to q in terms of value". While presenting a brief historical itinerary of development of the Logic of Preference, in this article it is attempted to survey, criticize, and modify some of its axioms introduced by Hallden. In correction of the said axioms, we have used notion of "necessity" as well as "S5" system in the modal logic in order to make relations of P and S more logically plausible.