Section 413. Limitation of other statutes

a. No other provision of law in
  any other statute which provides wholly or partly at the expense of  the
  state  or of a participating employer for pensions, retirement benefits,
  emoluments or awards for employees in  police  or  fire  service,  their
  widows  or  other dependents, shall apply to members or beneficiaries of
  the policemen's and firemen's  retirement  system  established  by  this
  article, their wiodws or other dependents.
    b. This article shall not:
    1.  Prevent  a  person  whose salary is paid from two or more sources,
  each entitling him to membership in a retirement system,  from  being  a
  member in all such systems, or
    2. Supersede or make inoperative the provisions of section two hundred
  twenty-seven  of the executive law in so far as they apply to an officer
  or employee in the division of state police of the executive  department
  who is a member of the retirement system.
    3.  Prevent  the extension of old-age and survivors insurance coverage
  to members of the policemen's and firemen's  retirement  system  or  the
  receipt  of benefits therefrom by such members, their wives or widows or
  their other dependents.
    4. Prevent a member of the policemen's and firemen's retirement system
  whose membership is authorized by paragraph nine  of  subdivision  c  of
  section  three  hundred  forty of this article, from receiving, upon his
  subsequent retirement from  the  policemen's  and  firemen's  retirement
  system,  benefits  based  on service not included in that upon which his
  retirement or pension from another pension or retirement  system  is  or
  would be based.
    5.  Prevent  payment  of a survivor's benefit, pursuant to section one
  hundred fifty-four of the civil service law, on account of the death  of
  a member of the retirement system.
    c.  The provisions of this article shall be operative, notwithstanding
  any contrary provision of law.