Section 72. Optional retirement at age fifty-five; closed plan

a. A member
  of  the  retirement  system  under age fifty-five who elected before May
  fifteenth, nineteen hundred  fifty,  to  contribute  to  the  retirement
  system  pursuant  to this section shall make additional contributions to
  the annuity savings fund over and above those required  to  be  made  by
  section  twenty-one  of  this  article.  The  rate  of  such  additional
  contributions shall be computed in a manner similar to that provided  by
  such section twenty-one. Such rate shall be computed to be sufficient to
  provide  an  annuity  at such age which, with the total pension provided
  for by subdivision b  of  section  seventy-five  of  this  article  will
  produce  a  retirement  allowance  of  one-sixtieth of his final average
  salary  for  each  year  of  his  total  service.  A  member's  rate  of
  contribution pursuant to this section shall be appropriately reduced for
  such    period    of   time   as   his   employer   contributes   toward
  pensions-providing-for-increased-take-home-pay   pursuant   to   section
  seventy-a  of this article. A retirement allowance, computed as provided
  in subdivision b of such section seventy-five, shall be payable upon the
  retirement of such member after he has attained age fifty-five.
    b. If any such member elected to contribute on the basis of retirement
  at age fifty-five after he had been credited with twenty or  more  years
  of  allowable  service, he may pay the additional contributions provided
  for by subdivision a of this section at any time within one  year  after
  he makes such election and prior to his retirement.
    c.  One  year  or more after the filing thereof, a member may withdraw
  his election to contribute on the basis of retirement at age  fifty-five
  pursuant  to  this  section.  Such withdrawal shall be by written notice
  duly  acknowledged  and  filed  with  the  comptroller.    Such   member
  thereafter  shall  contribute  on  the basis of retirement at age sixty.
  Such member, upon application before retirement and with the approval of
  the comptroller, shall be entitled to a refund  of  the  amount  of  his
  contributions  and  interest thereon which is in excess of the amount of
  the accumulated contributions which he would then have to his credit had
  he been contributing on the basis of retirement at age sixty.
    d. On or after May fifteenth, nineteen hundred fifty, no election  may
  be made to contribute pursuant to this section.
    e. The provisions of this section shall be controlling notwithstanding
  any provision in this article to the contrary.