(1) Upon retirement as provided in section 46, a supplemental member shall be paid a temporary straight life supplemental early retirement allowance terminating upon the supplemental member reaching age 62 years or his or her death, whichever occurs first. Prior to the effective date of retirement, the supplemental member may choose to be paid his or her retirement allowance under an optional form of payment provided in section 31(1)(a). For the purposes of this election, the provisions of section 31(1)(a) are modified to reflect the temporary nature of a supplemental early retirement allowance.

    (2) Subject to section 20j, the amount of the supplemental member’s temporary straight life supplemental early retirement allowance is equal to the difference between (i) 2.0% of his or her supplemental final average compensation multiplied by his or her covered service plus 1.5% of the supplemental member’s final average compensation multiplied by the excess, if any, of his or her credited service over his or her covered service; and (ii) the amount of retirement allowance paid under section 20.