The widow of an employee who withdraws after 10 or more years of service before age 55 and later attains such age while not in service, shall be entitled after his death to an annuity fixed on the date the employee becomes age 55.
The widow shall be entitled to the amount provided on a reversionary annuity basis from the following credits on the date when the annuity is fixed as follows:
(1) If service is 20 or more years, the total credits for widow's annuity and, in addition, if he was a present employee, the total credits for widow's prior service annuity; or(2) If service is 10 or more but less than 20 years the total credits for widow's annuity from employee contributions and 1/10 of the total credits for widow's annuity from city contributions for each year of service after the first 10 years, including, for the widow of a present employee, 1/10 of the total credits for widow's prior service annuity from city contributions for each year of service after the first 10 years.