Sec. 1.04. STATUTORY TRUST. (a) The fund is a statutory trust and is not a subdivision of government.

(b) The board shall hold in trust the assets of the fund for the exclusive benefit of the members and retirees of the fund and their beneficiaries and for defraying reasonable administrative expenses of the fund.

(c) The fund may not be diverted, transferred, or used for any purpose inconsistent with this Act and with the instruments governing the fund.

(d) A public or private entity, agency, or authority may not alter or impair any contract made by the board or under the authority or direction of the board.

(e) The fund is independent of the control of a municipality to which this Act applies.