(a) The city council adopts this amended and restated city general employees' retirement plan, as set forth in this article. The plan is intended to qualify under section 401(a) of the code and the trust created under the plan is intended to be exempt under section 501(a) of the code.

(b) The plan and the trust shall be maintained for the exclusive benefit of the employees of the city and their beneficiaries. No part of the trust fund can revert to the City, except as provided in this article, or be used for or diverted to purposes other than the exclusive benefit of employees of the city and their beneficiaries.

(c) Unless otherwise expressly provided, the amendments made to this plan, as amended and restated as of January 1, 1989, shall apply only to periods which commence on or after January 1, 1989, and shall not affect the benefits of a participant in pay status on January 1, 1989. (Code 1979, § 15-42)