Any amounts which may be paid or payable under the provisions of any workmen's compensation act, or pension act, or similar law, to a member, or to the dependents of a member on account of any disability or death, shall be offset against and payable in lieu. of any benefits payable out of funds provided by the city under the provisions of this retirement system on account of the same disability or death. In case the present value of the total benefits under said workmen's compensation act, pension act or similar law, is less than the present value of the pension otherwise payable from the firemen's and policemen's pension fund, then the present value of the payments shall be deducted from the present value of the pension and the remaining present value of the pension so reduced shall be payable in reduced actuarial equivalent amounts under the provisions of this retirement system.