As used in this chapter:
(1) "Income beneficiary" means the person to whom income is presently payable or for whom it is accumulated for distribution as income;
(2) "Inventory value" means the cost of property purchased by the trustee and the market value of other property at the time it became subject to the trust, but in the case of a testamentary trust the trustee may use any value finally determined for the purposes of an estate or inheritance tax;
(3) "Remainderman" means the person entitled to principal, including income which has been accumulated and added to principal;
(4) "Trustee" means an original trustee and any successor or added trustee.