Section 176. Definitions

1.  The  term "fund", as used in this article
  four-a, shall mean any public retirement system or  pension  fund  which
  grants  retirement  or  pension benefits to employees of the city of New
  York, employees of the state of New York, employees of any department or
  agency of the city of New York or the state of New York,  and  employees
  of any municipality or other participating employer participating in the
  New  York  state  employees'  retirement  system  or  the New York state
  policemen's and firemen's retirement system.
    2. The term "conventional mortgage", as used in this  article  four-a,
  shall  mean  (a)  any  single  bond  and  mortgage  or note and mortgage
  constituting  a  first  lien  upon  real  estate  (including   leasehold
  estates), not insured by the federal housing administrator or any of his
  successors  in  office  or  guaranteed  by  the  United States under the
  provisions of the national housing act, as amended or supplemented,  (b)
  first  mortgage  bonds issued under an indenture of mortgage and deed of
  trust, constituting a first lien upon real estate  (including  leasehold
  estates), and issued to a corporate trustee authorized to act as such in
  this state and approved by the fund.
    3.  The term "insured mortgage", as used in this article four-a, shall
  mean any single bond and mortgage or note and  mortgage  constituting  a
  first  lien  upon  real estate (including leasehold estates), insured by
  the federal housing administrator or any of his successors in office and
  guaranteed by the United States under the  provisions  of  the  national
  housing act, as amended or supplemented.