The employer shall have the right to amend the plan, at any time,
by adoption of the appropriate resolution or ordinance, and with respect
to any provisions thereof, and all parties thereto or claiming any
interest thereunder shall be bound thereby; provided, however, that
no amendment shall revise the accrued benefit of a participant determined
as of the later of the date such amendment is adopted or the date
such amendment becomes effective if such revised vested accrued benefit
is less than that computed under the plan without regard to such amendment.