1. The monthly supplemental pension to be paid to a state retired employee shall be computed by

1. (a) multiplying by forty (or forty-three and two-fifths in a case where a retired employee may under this act receive a maximum retirement allowance or pension, computed without optional modification, of thirteen hundred and two dollars) the number of years, not exceeding thirty, of allowable and credited service on which his retirement allowance or pension is based,
2. (b) subtracting therefrom the amount of his annual retirement allowance or pension, computed without optional modification, and
3. (c) dividing the results so obtained by twelve.

2. In no event shall the monthly supplemental pension paid to a state retired employee exceed

1. (a) twenty-five dollars, or thirty-three dollars and fifty cents in any case where the maximum under paragraph (b) of this subdivision is one hundred eight dollars and fifty cents, or

2. (b) an amount which, when added to an amount equal to one-twelfth of his annual retirement allowance or pension, computed without optional modification, exceeds

   1. (1) the sum of one hundred dollars, or
   2. (2) one hundred eight dollars and fifty cents, in the case of a state retired employee who attained age sixty-five before April first, nineteen hundred fifty-six, or who attains such age on or after such date, beginning with the month of April nineteen hundred fifty-six, if he is then sixty-five years of age or beginning with the month thereafter during which he attains age sixty-five, or who is a female person who attained age sixty-two before April first, nineteen hundred fifty-seven, or who attains such age on or after such date, beginning with the month of April nineteen hundred fifty-seven, if she is then sixty-two years of age or beginning with the month thereafter during which she attains age sixty-two, or is retired for disability, either before or after attaining age fifty, and who attained such age before April first, nineteen hundred fifty-seven, or who attains such age on or after such date, beginning with the month of April nineteen hundred fifty-seven, if he is then fifty years of age or beginning with the month thereafter during which he attains age fifty, or
   3. (3) one hundred eight dollars and fifty cents, in the case of a local retired employee, where the municipality shall have provided by local law, ordinance or resolution for payments up to such sum for local retired employees who attained age sixty-five before April first, nineteen hundred fifty-six, or who attain such age on or after such date, beginning with the month when such local law, ordinance or resolution shall become effective, if such local retired employee is then sixty-five years of age or beginning with the month thereafter during which he attains age sixty-five, or who are female persons who attained age sixty-two before April first, nineteen hundred fifty-seven, or who attain such age on or after such date, beginning with the month when such local law, ordinance or resolution shall become effective, if such local retired employee is then sixty-two years of age or beginning with the month thereafter during which she attains age sixty-two, or who are retired for disability, either before or after attaining age fifty, and who attained age fifty before April first, nineteen hundred fifty-seven, or who attain such age on or after such date, beginning with the month when such local law, ordinance or resolution shall become effective, if such local retired employee is then fifty years of age or beginning with the month thereafter during which she attains age fifty.

5. Notwithstanding any other provision of this act but except as otherwise provided by or pursuant to subdivision six and subdivision seven of this section, any state retired teacher who

1. (a) attained age sixty-five before April first, nineteen hundred fifty-six, or who attains such age on or after such date and who is receiving or is entitled to receive a supplemental pension pursuant to this act on or after such date shall, beginning with the month of April, nineteen hundred fifty-six, if he is then sixty-five years of age or beginning with the month thereafter during which he attains age sixty-five, or
2. (b) is a female person who attained age sixty-two before April first, nineteen hundred fifty-seven, or who attains such age on or after such date and who is receiving or entitled to receive a supplemental pension pursuant to this act on or after such date shall, beginning with the month of April, nineteen hundred fifty-seven, if she is then sixty-two years of age or beginning with the month thereafter during which she attains age sixty-two, or
3. (c) is retired for disability, either before or after attaining age fifty, and who attained such age before April first, nineteen hundred fifty-seven, or who attains such age on or after such date and who is receiving or entitled to receive a supplemental pension pursuant to this act on or after such date shall, beginning with the month of April, nineteen hundred fifty-seven, if he is then fifty years of age or beginning with the month thereafter during which he attains age fifty, receive a monthly supplemental pension in an amount which when added to his monthly retirement allowance or pension, computed without optional modification, including any modification due to additional contributions as authorized by subdivision three of section five hundred sixteen of the education law shall be equal to one hundred eight dollars and fifty cents; provided, however, that this subdivision shall not become operative in the case of a local retired teacher unless and until a local law, ordinance or resolution authorizing such additional supplemental pension payments for such a person or persons shall have become effective. receive a monthly supplemental pension in an amount which when added to his monthly retirement allowance or pension, computed without optional modification, shall be equal to one hundred eight dollars and fifty cents; provided, however, that this subdivision shall not become operative in the case of a local retired teacher unless and until a local law, ordinance or resolution authorizing such additional supplemental pension payments for such a person or persons shall have become effective.