Before revision:  An ELMD is a strictly positive process that , when deflated by it, discounted nonnegative wealth processes become local martingales. In terms of measures, absence of arbitrages of the first kind is shown to be equivalent to the existence of a finitely additive probability, weakly equivalent to the original and locally countably additive, under which the discounted asset-price process is a "local martingale ". Finally, the aforementioned results are used to obtain an independent proof of the FTAP .
After revision:  An ELMD is a strictly positive process that acts as a local martingale deflator on nonnegative wealth processes .