This paper offers an accessible introductory survey of the application of abstract choice theory to consumer theory. In the process, the paper identifires---somewhat more carefully than is usual in the literature--- the relatively small role of the rationality postulates and the relatively large...

In this paper we first show that if a not-necessarily-self-financing portfolio has instantaneously riskless internal gains, then on an infinitesimal time-interval, the increase in the internal gains on the portfolio is the same as the change in the price of that amount of bonds which has the...