In chapter 3 through 8 we developed a theory for the analysis of financial benefits contingent on the time of death of a single life. We can extend this theory to benefits involving several lives. An application of this extension commonly found in pension plans is the joint-and-survivor annuity option. Other applications of multiple life actuarial calculations are common. In estate and gift taxation, for example, the investment income from a trust can be paid to a group of heirs as long as at least one of the group survives. Upon the last death, the principal from the trust is to be donated to a qualified charitable institution. The amount of the charitable deduction allowed for estate tax purposes is determined by an actuarial calculation. There are family policies in which benefits differ due to the order of the deaths of the insured and the spouse, and there are insurance policies with benefits payable on the first or last death providing cash in accordance with an estate plan.