 A basic rationality constraint on the preference relation has already been discussed—that it weakly orders the options (i.e., satisfies Transitivity and Completeness). The following notation will be used to introduce the two additional vNM axioms of preference: \(\{pA, (1-p)B\}\) denotes a lottery that results either in \(A\), with probability \(p\), or \(B\), with probability \(1-p\), where \(A\) and \(B\) can be final outcomes but can also be lotteries.