1121.11. Where an amount is deemed by section 1121.10 to have been paid or to have become payable on 15 December of a calendar year by a trust to a beneficiary who was not a beneficiary under the trust at that time, the following rules apply:(a) notwithstanding any other provision of this Act, where the beneficiary did not exist at that time, except for the purposes of this paragraph, the first taxation year of the beneficiary is deemed to include the period that begins at that time and ends immediately before the beginning of the first taxation year of the beneficiary;
(b) the beneficiary is deemed to exist throughout the period described in paragraph a; and
(c) where the beneficiary was not a beneficiary under the trust at that time, the beneficiary is deemed to have been a beneficiary under the trust at that time.