Alfred Anderson’s will established a testamentary trust for the benefit of his wife, Alma Anderson, during her lifetime. Alma and their son, John, were appointed trustees. The trustees were directed to make payments to Alma from the trust principal in amounts necessary for her “comfort, support, and maintenance.” Alfred and Alma’s daughter, Kathleen Best, was appointed personal representative of Alfred’s estate. Best paid estate taxes to the IRS. The IRS determined that there was a deficiency in the amount of estate taxes paid, finding that the trust assets were included in Alma’s gross estate, and requested additional estate taxes and interest, which Best paid. Best (plaintiff) filed a claim with the IRS (defendant) for a refund of these additional estate taxes and interest. The IRS denied the claim, finding that the trust assets were included in Alma’s gross estate because she held a general power of appointment over the trust assets. Best appealed, arguing that Alma did not possess a general power of appointment, but instead had a power of appointment that was limited to an ascertainable standard.