Game theory is properly a branch of mathematics. As such it is concerned with assertions which can be proved to be true if certain other assertions are true. This way of establishing truth by reference to assertions previously established as true would lead to infinite regress unless certain fundamental assertions were simply accepted as true (without proof). These basic assertions are called axioms. Assertions whose truth is derived by logical proof are called theorems. Game theory, like any other mathematical theory, is essentially a collection of theorems derived from axioms...